MACROCYCLIC IMMUNOMODULATORS

Abstract: Immunomodulatory macrocylic compounds having the formula (VII) and pharmaceutically acceptable salts, esters, amides and prodrugs thereof, wherein X is selected from one of the formulae (Ia), (Ib) and (Ic), as well as pharmaceutical compositions containing the same.

Description: MACROCYCLIC IMMUNOMODULATORS This application is a continuation-in-part of copending United States patent application Serial No. 07/755,208, filed September 5, 1991. Field of the Invention The present invention relates to novel chemical compounds having immunomodulatory activity, and in particular to macrolide immunosuppressants. More particularly, the invention relates to semisynthetic analogs of ascomycin, means for their preparation, pharmaceutical compositions containing such compounds and methods of treatment employing the same. Background of the Invention The compound cyclosporine (cyclosporin A) has found wide use since its introduction in the fields of organ transplantation and immunomodulation, and has brought about a significant increase in the success rate for transplantation procedures. Unsatisfactory side- effects associated with cyclosporine, however, such as nephrotoxicity, have led to a continued search for immunosuppressant compounds having improved efficacy and safety. Recently, several classes of macrocyclic compounds having potent immunomodulatory activity have been discovered. Okuhara et al, in European Patent Application No. 184162, published June 11, 1986, disclose a number of macrocyclic compounds isolated from the genus Streptomyces. Immunosuppressant FK-506, isolated from a strain of S. tsuk baensis , is a 23-membered macrocyclic lactone represented by formula la, below. Other related natural products, such as FR-900520 (lb) and FR-900523 (lc), which differ from FK-506 in their alkyl substituent at C-21, have been isolated from S. hygroscopicus yakushimnaensis. Yet another analog, FR-900525, produced by S. tsukubaensis, differs from FK-506 in the replacement of a pipecolic acid moiety with a proline group. FR-900520, also known as ascomycin, has been previously disclosed by Arai et al. in U.S. Patent No. 3,244,592, issued April 5, 1966, where the compound is described as an antifungal agent. Monaghan, R.L., et al ., on the other hand, describe the use of ascomycin as an immunosuppressant in European Patent Application No. 323865, published July 12, 1989. Although the immunosuppressive activity of FK-506 has been clinically confirmed, toxicity in mammals has limited its utility. The activity of FK-506 has, however, prompted efforts to discover novel analogs of FK-type compounds which possess superior properties. These efforts include the isolation of new fermentation products, the microbial transformation of existing chemical entities, the chemical modification of these macrocycles, and the synthesis of hybrid species derived from smaller synthetic fragments. 1(a): FK-506 R = CH 2 CH=CH 2 ; n=l 1(b): FR-900520 R = CH 2 CH 3 ; n=l 1(c): FR-900523 R = CH 3 ; n=l 1(d): FR-900525 R = CH 2 CH=CH 2 ; n=0 Fermentation products of FK-type compounds include C-21-epi derivatives of FK-506; a31-demethylated derivative of FK-506; 31-oxo-FK-506; and compounds derived from FK506, FR-900523, and FR-900525 which are characterized by the introduction of hydroxy- protecting groups, formation of a double bond by elimination of water between carbons 23 and 24, oxidation of the hydroxy group at carbon 24 to the ketone, and reduction of the allyl side- chain at carbon 21 via hydrogenation. Other published metabolites include those derived from FK-506 and FR-900520 where the lactone ring is contracted to give a macrocyclic ring containing two fewer carbons. Several microbial transformations of FK-type compounds at carbon 13 have been published, such as the microbial demethylation of FR-900520 to form the bisdemethylated 13,31-dihydroxy ring-arranged derivative of FR-900520; the microbial monodemethylation of FK-506 and FR-900520, respectively; and the microbial demethylation of FR-900520 at C-31, as well as a number of other macrocyclic microbial transformation products. Numerous chemical modifications of the FK-type compounds have been attempted. These include the preparation of small synthetic fragments of FK-type derivatives; a thermal rearrangement of a variety of derivatives of FK-506 which expands the macrocyclic ring by two carbons; and modifications which include methyl ether formation at C-32 and/or C-24, oxidation of C-32 alcohol to the ketone, and epoxide formation at C-9. Although some of these modified compounds exhibit immunosuppressant activity, the need remains for macrocyclic compounds having immunosuppressive activity which do not have the serious side effects frequently associated with immunosuppressant therapy. Accordingly, one object of the invention is to provide novel semisynthetic macrolides which possess the desired immunomodulatory activity but which may be found to minimize untoward side effects. Another object of the present invention is to provide synthetic processes for the preparation of such compounds from starting materials obtained by fermentation. A further object of the invention is to provide pharmaceutical compositions containing, as an active ingredient, one of the above compounds. Yet another object of the invention is to provide a method of treating a variety of disease states, including post-transplant tissue rejection and autoimmune disfunction. Summary of the Invention In one aspect of the present invention are disclosed compounds having the formula and pharmaceutically acceptable salts, esters, amides and prodrugs thereof. In formula VII, n is zero or one, and R and R' are chosen such that one of R and R' is hydrogen and the other is selected from the group consisting of methyl, ethyl, 2-hydroxyethyl, propyl, cyclopropylmethyl, 2-oxopropyl, 2-ethanal, allyl, -CH 2 CH 2 OC(O)R 10 where R 10 is aryl, -CH 2 C(O)R 12 , -CH 2 C(0)N(R 1 ' )(CH 2 ) m CH(R 16 )C(0)R 12 , -CH 2 C(0)N(R 14 ')(CH 2 ) m CH(R l 6)C(0)N(Rl 4" )(CH 2 ) m €H(R l6' )C(0)R 12 , and -CH 2 C(O)N(R 14, )(CH 2 ) m CH(Rl6)C(0)N(Rl 4 ")(CH 2 ) m -CH(Rl6')C(0)N(Rl4 ,π )- (CH2)m π CH.(R I6, ')C(0)R 12 . In these formulae, m, m' and m" are independently zero to six; R 16 , R 16' and R 16 " are independently selected from hydrogen, loweralkyl, hydroxyloweralkyl, carboxyalkyl, thioloweralkyl, thioalkoxyalkyl, guanidinoalkyl, aminoalkyl, arylalkyl and, if m, m' and m" are other than zero, amino or amidoalkyl; and R 12 is selected from (i) hydroxy, (ii) -OR 13 where R 13 is loweralkyl, cycloalkyl, cycloalkylalkyl or arylalkyl, and (iϋ) -NR 14 R 15 wherein R 14 , R 14 ', R 14" and R 14"' are independently selected from hydrogen, loweralkyl, arylalkyl, cycloalkyl and cycloalkylalkyl and R 15 is selected from hydrogen, loweralkyl, arylalkyl, cycloalkyl, cycloalkylalkyl, aminoalkyl, hydroxyalkyl, carboxyalkyl, and thioloweralkyl; or, taken together, R 14 and R 15 are -(CH ) q - where q is two to five; or, taken together with the nitrogen to which they are attached, R 14 and R 15 form a group selected from morpholiπo and iperidino; or, taken together, one or more of R 14 ' and R 16 , R 14 " and R 16 ', and R 14 '" and R 16 " are -(CH 2 ) p - where p is two to five. Alternatively, one of R and R', taken together with one of R 35 and R 36 (described below), forms a C-21/C-22 bond and the other of R and R', taken together with the other of R 35 and R 36 , is a heterocycle-forming group having a formula selected from -N(R 63 )CH=CH- and -OCOR. 6 )^!!- where the heteroatom in each instance is connected to C-22, R 63 is selected from hydrogen, loweralkyl, arylalkyl and aryl, and R 64 is hydrogen or loweralkyl. X in formula VH is a group having one of the following subformulae: in which R 1 is selected from the group consisting of (a) hydrogen; (b) halogen; (c) triflate; (d) mesylate; (e) tosylate; (f) benzenesulfonate; (g) azide; (g 1 ) cyanate; (h) -OC(S)OR 11 , wherein R 11 is selected from loweralkyl, arylalkyl and aryl; (i) -OC(0)R 19 , wherein R 19 is selected from (i) hydrogen, (ii) loweralkyl, (iii) arylalkyl, (iv) aminoalkyl, (v) aryl and (vi) an alpha- carbon with an optionally protected alpha-amino, and appended side-chain of a standard alpha- amino acid; (j) -OC(0)NHR 17 , wherein R 17 is selected from hydrogen, loweralkyl, arylalkyl, aryl, and -SR 14 ; (k) -OC(0)OR ; (1) -OP(0)(ORH) 2 ; (m) -OR 11 ; (n) -0(CH 2 ) j C(0)R 12 where j is one to five; (0) -0(CH 2 ) j C(0)N(R 14 ')(CH 2 ) m CH(R 16 )C(0)R 12 ; (p) -0(CH 2 ) j C(0)N(R 4, )(CH 2 ) m CH(R 16 )-C(0)N(R 14,r )(CH 2 ) m CH(R 1 6 , )-C(0)R 12 ; q) -O(CH 2 ) j C(O)N(R 14 ')(CH 2 ) m CH(R 16 -C(O)N(R 14 ")(CH 2 ) m CH(R 16• )- C(0)N(R l '* m )(CH2)ιn"CH(R l6π )C(0)R l2 ; (r) -SR 17 ; (s) -SC(0)RH; (t) -P(0)(OR ) 2 ; (u) 1-tetrazolyl; (u') 2-tetrazolyl; (v) -NHC(NH)NH 2 ; (w) -C(NH)NH 2 ; (x) -0-(hydroxyl protecting group); (x') -O-tert-butyldimethylsUyl; (y) -HNSR 11 ; (z) -NR 17 S(0) R π ; (aa) -NR 17 C(0)R 18 , wherein R 18 is selected from hydrogen, loweralkyl, arylalkyl, aryl, -NR 1 R 17 and -NR 14 R 14 ; (bb) -NR 17 C(0)NHR 18 ; (cc) -NR 17 C(0)OR π ; (dd) -NHP(O)(OR u ) 2 ; (ee) a group having the formula (Ie); (ff) a group having the formula (If) where R 20 and R 20' are independently selected from the group consisting of hydrogen, aryl, cyano, trifluoromethyl, -C(0)-0-loweralkyl and -C(0)-loweralkyl; (gg) a group having the formula (lg); and (hh) hydroxy. R 2 in subformula lb is hydrogen or trifluoromefhylcarbonyl or, taken together with R 2' , forms a diazo group or, taken together with one of R 3 and R 4 , forms a C-32/C-33 bond. R 2' in subformula lb is hydrogen or, taken together with R 2 , forms a diazo group. R 3 and R 4 in subformula lb are chosen such that (a) both are thioloweralkoxy, thioaryloxy or thioarylalkoxy; (b) one of R 3 and R 4 is selected from hydrogen, hydroxy and a C-32/C-33 bond formed with R 2 , and the other of R 3 and R 4 is hydrogen or R 11 ; or (c) taken together, R 3 and R 4 form a group selected from (i) oxo, (ii) =NR 48 where R 48 is selected from arylalkoxy, hydroxy, -0(CH )fCOOH where f is one to five, -NHC(0)OR 39 where R 39 is loweralkyl, and -NHS(O) 2 R 4 0 where R 4 ° is aryl, (iii) =NOR 222 or =N+(0-)R 222 , where R 222 is lowerlkyl, aryl, -S0 -(loweralkyl) or -S0 -(aryl), and (iv) a thioketal-forming moiety having the formula -S-(CH ) r -S- where r is two or three. R 5 in subformula Ic is selected from the group consisting of formyl and -CI^OR 1 , where R 1 is as defined above. Y in formula VII is a group selected from the subformulae (TUa) and (UJa'), in which R 31 and R 32 are chosen such that one of R 31 and R 32 is hydrogen and the other is independently selected from the group consisting of (i) hydrogen, (ii) hydroxy, (iii) -R 17 , (iv) -C^R 11 and (v) -CH(R 11 )NHR 17 . Alternatively R 31 and R 32 , taken together, form a diazo group; or, taken together with one of R 33 and R 34 , one of R 31 and R 32 forms a C-23/C-24 bond and the other is selected from hydrogen, alkyl, -C(0)NHR 61 , -S(0) 2 R 61 and -C(0)OR 61 , where R 61 is hydrogen, aryl or loweralkyl; or, taken together with one of R 33 and R 34 , one of R 31 and R 32 forms a group having the formula (in C-23 to C-24 orientation) or, taken together with one of R 35 and R 36 , one of R 31 and R 32 forms a C-22/C-23 bond and the other is selected from hydrogen, alkyl, -C(0)NHR 61 , -S(0) 2 R 61 and -C(0)OR 61 ; or R 31 and R 32 , together with carbon atom C-23 to which they are attached, may be absent and replaced by a C-22/C-24 bond, as shown in subformula DTa', above. One or both of R 31 and R 32 may also, when taken together with one or both of R 33 and R 34 and the carbon atoms to which they are attached, form (i) a fused indole group wherein the nitrogen atom is adjacent to C-24, (ii) a fused, optionally unsamrated, 5-membered heterocyclic group wherein one of the two ring members adjacent to C-23 and C-24 is oxygen, the other adjacent ring member is -CHR 17 - or =CR 17 -, and the remaining ring member is =N- or -NR 11 -; or (iii) a fused pyrrole. Furthermore, taken together with R 35 and R 36 and the carbon atoms to which they are attached, R 31 and R 32 may form (i) a fused indole group wherein the nitrogen atom is adjacent to C-22 or (ii) a fused furan ring wherein the oxygen atom is adjacent to C-22. R 35 and R 36 in subformulae Ilia and JTIa' are chosen such that both are loweralkoxy; or that one of R 35 and R 36 is hydrogen and the other is selected from hydroxy, amino, -NHR 17 , -OC(0)R u , -OC(0)0-(benzyl) and -NHNH-(tosyl); or (in subformula Dla), taken together with one of R 31 and R 32 , one of R 35 and R 36 forms a C-22/C-23 bond and the other is hydrogen or hydroxy; or (in subformula ϋla 1 ), taken together with one of R 33 and R 34 when C-23 is absent, one of R 35 and R 36 forms a C-22/C-24 bond and the other is hydrogen or hydroxy; or, taken together with one of R 33 and R 34 , one of R 35 and R 36 forms a group having the formula -OC(CH3) 2 0-; or, taken together, R 35 and R 36 form an oxo group or =NR 38 where R 38 is selected from (i) arylalkoxy, (ii) hydroxy, (iii) -OCH COOH, (iv) -OCH 2 CHCH 2 , (v) -NHC(0)OR 39 and (vi) -NHS(0) R 40 . Alternatively, taken together with R and R 1 , R 35 and R 36 may form a C-21/C-22 bond and a heterocycle-forming group as described above or, taken together with R 31 and R 32 , R 35 and R 36 may form an indole or furan group as described above. As a further alternative, when taken together with either or both of R 33 and R 34 and intervening carbon atoms C-22, C-23 and C-24, R 35 and R 36 may form a fused, heterocyclic group selected from either (i) a five- or six-membered, unsaturated group which comprises a heteroatom selected from N, O and S, optionally comprises a second heteroatom selected from N, O and S with the proviso that when two heteroatoms are present, at least one is N, and is optionally substituted with loweralkyl, aryl, arylalkyl, amido, formyl, -C^OR 11 or -C(0)R 41 where R 41 is loweralkyl, or (ii) a seven-membered, optionally unsaturated group having fused thereto a phenyl group optionally substituted with loweralkyl, alkoxy or halogen, wherein the ring member adjacent to C-22 is =N- and the ring member adjacent to C-24 is O or S. R 33 and R 34 in subformulae πia and Ilia' are chosen such that (i) one of R 33 and R 34 is hydrogen and the other is selected from hydrogen, hydroxy, amino, -OR 11 , -ON0 , -OC(0)NHR 17 , -C(0)R n , -C(R n )NHR 17 and -0-(hydroxyl protecting group); (ii) one of R 33 and R 34 is hydrogen and the other forms, with one of R 31 or R 32 , a group having the formula -CH(R 11 )NHCH(C(O)OR 11 )- or, with one of R 35 and R 36 , a group having the formula -OC(CH3) 0-; or (iii) one of R 33 and R 34 forms a C-23/C-24 bond (or, when C-23 is absent, a C-22/C-24 bond) and the other is selected from hydrogen, hydroxy and loweralkoxy. Alternatively, when taken together, R 33 and R 34 may form an oxo group or, taken together with one or more of R 31 , R 32 , R 35 and R 36 and the intervening carbon atoms, one or both of R 33 and R 34 form a group selected from (i) indole, where the nitrogen atom is adjacent to C-24, (ii) furan, with the oxygen atom attached to C-24, or (iii) a heterocyclic group, as described above. Z in formula VII is selected from groups having the subformulae R 21 and R 22 are chosen such that (i) one of R 21 and R 22 is hydrogen and the other is selected from hydrogen, loweralkyl, arylalkyl, aryl, halogen, triflate, mesylate, tosylate, benzenesulfonate, azide, amine, acetate, -NR 17 R 18 , -OC(0)R 19 , -NR 17 S(0) 2 R 18 , -NR 17 C(0)R 18 , and groups having the formulae (If) and or, taken together with R 23 , forms a C-9/C-10 bond. Alternatively, one of R 21 and R 22 may be hydroxy and the other selected from hydrogen, loweralkyl, arylalkyl and aryl; or one of R 21 and R 22 may be selected from hydrogen, loweralkyl and arylalkyl and the other, taken together with R 23 and the carbon atoms to which they are attached, may form a fused, five-membered heterocyclic group wherein the two ring members adjacent to C-9 and C-10 are oxygen and the remaining ring member is selected from -C(0)- and -C(S)-; or one of R 21 and R 22 may be selected from hydrogen, loweralkyl and arylalkyl and the other, taken together with R 23 and the carbon atoms to which they are attached, may form a fused, five-membered heterocyclic group wherein the two ring members adjacent C-9 and C- 10 are oxygen and the remaining ring member is -P(0)(R 25 )- where R 25 is loweralkyl, arylalkyl, loweralkoxy, amino or loweralkylamino. As a further alternative, R 21 and R 22 , when taken together, may form a group selected from oxo, oxime and -0-CH s or R 21 and R 22 , taken together with the carbon to which they are attached, may be absent and C-8 attached directly to C-10. R 23 in subformula Ha is selected from the group consisting of hydroxy, halogen, amino, loweralkylamino, arylaUcylaπiino, loweralkoxy and arylalkoxy or, taken together with one of R 21 and R 22 , forms a C-9/C-10 bond or, taken together with R 24 , forms a C-lO/C-11 bond. R 24 in subformula Ha is hydrogen or, taken together with R 23 , forms a C-lO/C-11 bond. R 26 , R 27 , R 28 and R 29 in subformula lib are chosen such that (i) one of R 28 and R 29 is hydroxy and the other is -COOH or -C(0)0-loweralkyl, and (ii) R 26 and R 27 and the carbon to which they are attached are absent and C-8 is directly attached to C-10; or, taken together, R 26 and R 27 are oxo while one of R 28 and R 29 is hydroxy and the other forms a C-2/C-10 bond; or, taken together, R 26 and R 28 form a bond and R 27 and R 29 form a group having the formula -U-C(R n )=N- in which U is adjacent to C-9 and is selected from -0-, -S- and -NH-; or R 26 and R 28 are each hydroxy and R 27 and R 29 , taken together, form a group having the formula -CH 2 -C(CH 2 )-CH 2 -. Alternatively, R 26 , R 27 , R 28 and R 29 , when taken together with the carbon atoms to which they are attached, may form either (i) a fused naphthalene group wherein the atoms adjacent to C-9 and C-10 are substituted by cyano groups, or (ii) a fused, mono-, bi- or tricyclic heterocyclic aromatic group comprising fused, six-membered rings, which has between one and three nitrogen heteroatoms and is optionally substituted with up to six groups selected from amino, halogen, loweralkyl and loweralkoxy. R 60 and R 65 in subformula lib are chosen such that R 65 is hydrogen and R 60 is selected from the group consisting of (i) hydrogen, (ii) hydroxy and (iii) -OC(0)R 19 or, taken together, R 60 and R 65 may form an oxo group. When examined for immunomodulatory activity using a common in vitro biological assay, the compounds of the invention are seen to be potent immunosuppressant agents. Consequently, it is expected that the compounds may be found to possess immunosuppressive, antimicrobial, antifungal, antiviral, antiinflammatory, and antiproliferative activity, as well as the ability to reverse chemotherapeutic drug resistance. Accordingly, in another aspect of the present invention are disclosed pharmaceutical compositions comprising a compound of the invention in combination with a pharmaceutically acceptable carrier. Suitable carriers and methods of formulation are also disclosed. In a further aspect of the present invention are disclosed processes for the preparation of the above compounds, synthetic intermediates useful in the preparations of these and other immunomodulator derivatives of ascomycin, and methods of immunomodulatory treatment by the administration of a therapeutically effective amount of a compound of the invention to a patient in need of such treatment. Detailed Description of the Invention The compounds of the present invention are formed by modification of FR-900520 (ascomycin) or one of its congeners (such as FK-506, etc.) in one or more of three general regions. Accordingly, representative compounds of the invention may be categorized as belonging to one of several classes, depending on the number of modifications present. Singly-modified compounds, i.e., those in which two of the three general regions remain unchanged over the parent molecule, are encompassed by the formulae and and the pharmaceutically acceptable salts, esters, amides and prodrugs thereof, wherein each of the substituents is as defined above. Among the compounds characterized by formula I are the most preferred compounds of the present invention, including that of Example 137 below which is regarded as the best mode hereof. Also among the compounds of formula I are preferred derivatives useful as intermediates in the synthesis of other immunomodulators, and especially compounds in which X is a group of the formula (lb'), wherein R 221 is selected from =NOR 222 and =N + (0")R 222 . In these intermediates, R 222 is chosen from among lowerlkyl, aryl, -S0 2 -(loweralkyl) and -S0 2 -(aryl). On the other hand, doubly-modified analogs of ascomycin which are representative of the compounds of the invention may be described by the formulae and the pharmaceutically acceptable salts, esters, amides and prodrugs thereof, wherein each of the substituents again are as previously defined. Among these doubly-modified compounds are those in which a direct bond is formed between carbon atoms C-2 and C-10, represented by the structural formula Multiple modifications are also possible by the careful selection of syntheses from those disclosed herein as well as by the use of other synthetic methods known to those skilled in the art, and result in the compounds belonging to the representative class encompassed by formula VII, above. Representative and preferred compounds of the invention include those encompassed within formulae HI, V, VI, VII and Vm wherein Y is selected from the group consisting of -14- wherein R 11 , R 17 , R 31 , R 32 , R 3δ and R 41 are as previously defined; R 81 is selected from hydrogen, alkyl, -C(0)NHR 61 , -S(0) 2 R 61 and -C(0)OR 61 ; R 82 and R 83 are independently selected from hydroxy and amino; R 84 is hydrogen, hydroxy or loweralkoxy R 85 is hydrogen or hydroxy; R 86 is selected from hydrogen, loweralkyl, aryl, arylalkyl, amido, formyl, -C(0)R 41 and -C(0)OR 41 ; R 87 is selected from hydrogen, halogen, alkoxy and loweralkyl; V is selected from oxygen, -N(R 86 )- and -NC(0)R 86 - ; and W is oxygen or sulfur. Other representative compounds of the invention include those encompassed within formulae II, IV, VI and VII wherein Z is selected from the group consisting of wherein R 11 , R 21 , R 22 , R 23 and U are as previously defined; R 70 is hydrogen, loweralkyl or arylalkyl; R 71 is hydrogen or loweralkyl; R 72 is oxygen or sulfur; and A, D, E, G, J and L are selected from nitrogen, carbon and -C(R 73 )- where R 73 is amino, halogen, loweralkyl or loweralkoxy. As used throughout this specification and in the appended claims, the following terms have the meanings specified: The terms "alkoxy" and "loweralkoxy" as used herein refer to a loweralkyl group, as defined below, attached to the remainder of the molecule through an oxygen atom. Alkoxy and loweralkoxy groups include, for example, methoxy, ethoxy, isopropoxy, n-butoxy, sec- butoxy, isobutoxy, tert-butoxy and the like. The term "a kyl" as used herein refers to a monovalent straight chain or branched chain group of 1 to 12 carbon atoms including, but not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, ϊsobutyl, tert-butyl and the like. The terms "alkylamino" and "loweralkylamino" as used herein refers to a group having the structure -NH-(loweralkyl), where the loweralkyl portion is as defined below. AUcylaπiino and loweralkylamino groups include, for example, methylamino, ethylamino, isopropylamino and the like. The term "amidoalkyl" as used herein refers to a group having the structure -NRiOiC^RlO 2 appended to a loweralkyl group, as previously defined. The groups R 101 and RiO 2 are independently selected from hydrogen, lower alkyl, aryl, arylalkyl, and halosubstituted alkyl. Additionally, RiO* and Ri0 , taken together, may optionally be -(CH 2 )aa- where aa is an integer of from 2 to 6. The term "aminoalkyl" as used herein refers to a group having the structure -NRiCBRKM appended to a loweralkyl group, as previously defined. The groups R 1 ^ 3 and R104 are independently selected from hydrogen, lower alkyl, aryl and arylalkyl. Additionally, R103 and Ri04, taken together, may optionally be -(CH 2 ) b tr where bb is an integer of from 2 to 6. The term "aryl" as used herein refers to substituted and unsubstituted carbocyclic aromatic groups including, but not limited to, phenyl, 1- or 2-naphthyl, fluorenyl, (1,2)- dihydronaphthyl, (l,2,3,4)-tetrahydronaphthyl, indenyl, indanyl and the like, optionally substituted with 1, 2 or 3 substituents independently selected from halo, nitro, cyano, Ci to Cι 2 alkyl, alkoxy and halosubstituted alkyl. The term "arylalkoxy" as used herein refers to an arylalkyl group, as previously defined, attached to the parent molecular moiety through an oxygen atom. Arylalkoxy includes, but is not limited to, benzyloxy, 2-phenethyloxy, 1-naphthylmethyloxy and the like. The term "arylalkyl" as used herein refers to an aryl group, as previously defined, appended to an alkyl group including, but not limited to, benzyl, 1- and 2-naphthylmethyl, halobenzyl, alkoxybenzyl, hydroxybenzyl, aminobenzyl, nitrobenzyl, guanidinobenzyl, fluorenylmethyl, phenylmethyl(benzyl), 1-phenylethyl, 2-phenylethyl, 1-naphthylethyl and the like. The term "arylalkylamino" as used herein refers to a group having the structure -NH-(arylalkyl), where the arylalkyl portion is as previously defined. Examples of arylalkylamino groups include benzylamino, 1-phenylethylamino and the like. The term "aryloxy" as used herein refers to an aryl group, as previously defined, attached to the parent molecular moiety through an oxygen atom. Aryloxy includes, but is not limited to, phenoxy, 1-naphthoxy, 2-naphthoxy and the like. The term "carboxyalkyl" as used herein refers to a carboxyl group, -C0 2 H, appended to a loweralkyl group, as previously defined. The term "cycloalkyl" as used herein refers to cyclic groups of 3 to 8 carbons including, but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. The term "cycloalkylalkyl" as used herein refers to a cycloalkyl group appended to a lower alkyl group including, but not limited to, cyclohexylmethyl and cyclohexylethyl. The term "guanidinoalkyl" as used herein refers to a group of the structure -NR105C(=NR 1 06)NHR 1 0 7 appended to a loweralkyl group, as previously defined. RiOS, R106, and RlW are independently selected from hydrogen, lower alkyl, heterocyclic, aininoalkyl and aryl. Alternatively, R106, and R107, taken together, may optionally be -(CH 2 )cc~ wherein cc is an integer of from 2 to 6. The terms "halo" and "halogen" as used herein refer to an atom selected from fluorine, chlorine, bromine and iodine. The term "heterocyclic" as used herein, except where otherwise specified, refers to any aromatic or non-aromatic 5-, 6- or 7-membered ring or a bi- or tri-cyclic group comprising fused six-membered rings having between one and three heteroatoms independently selected from oxygen, sulfur and nitrogen, wherein (i) each 5-membered ring has 0 to 2 double bonds and each 6-membered ring has 0 to 3 double bonds, (ii) the nitrogen and sulfur heteroatoms may optionally be oxidized, (iii) the nitrogen heteroatom may optionally be quaternized, and (iv) any of the above heterocyclic rings may be fused to a benzene ring. Representative heterocycles include, but are not limited to, pyrrolyl, pyrrolidinyl, pyrazolyl, pyrazolinyl, pyrazolidinyl, imidazolyl, imidazolinyl, imidazolidinyl, pyridyl, piperidinyl, pyrazinyl, piperazinyl, pyrimidinyl, pyridazinyl, oxazoyl, oxazolidinyl, isoxazolyl, isoxazolidinyl, morpholinyl, indolyl, quinolinyl, thiazolyl, thiazolidinyl, isothiazolyl, isothiazolidinyl, isoquinolinyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, furyl, thienyl and benzothienyl. The terms "hydroxyalkyr and "hydroxyloweralkyl" as used herein refer to -OH appended to a loweralkyl group, as defined below. The term "hydroxy-protecting group" as used herein refers to those groups which are known in the art to protect a hydroxyl group against undesirable reaction during synthetic procedures and to be selectively removable including, but not limited to, methylthiomethyl, rert-dimethylsilyl, rerr-butyldiphenylsilyl, acyl substituted with an aromatic group and the like. The term "loweralkyl" as used herein refers to an alkyl group, as defined above, of 1 to 8 carbon atoms. The terms "naturally occuring amino acid" and "standard amino acid" refer to an amino acid selected from the group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine. The term "N-terminal protecting group" as used herein refers to those groups known in the art to protect the N-terminus against undesirable reactions during synthetic procedures or to prevent the attack of exopeptidases on the final compounds or to increase the solubility of the final compounds and includes, but is not limited to acyl, acetyl, pivaloyl, tert-butylacetyl, tert- butyloxycarbonyl (Boc), carbobenzyloxycarbonyl (Cbz), and benzoyl groups. Other such groups are described by Gross, E. and Meienhofer, J. in "The Peptides", Volume 3; Academic Press, 1981. The terms "thioalkoxy" and "thioloweralkoxy" as used herein refer to a loweralkyl group, as previously defined, attached to the remainder of the molecule through a sulfur atom. Examples of thioalkoxy and thioloweralkoxy groups include, but are not limited to, thiomethoxy, thioethoxy, thioisopropoxy, n-thiobutoxy, sec-thiobutoxy, isothiobutoxy, tert- thiobutoxy and the like. The term "thioalkoxyalkyl" as used herein refers to a thioalkoxy group, as defined above, appended to a loweralkyl group. The term "thioarylalkoxy" as used herein refers to an arylalkyl group, as previously defined, attached to the remainder of the molecule through a sulfur atom. The term "thioaryloxy" as used herein refers to an aryl group, as defined above, attached to the remainder of the molecule through a sulfur atom. The term "thioloweralkyl" as used herein refers to a loweralkyl group, as defined above, attached to the remainder of the molecule through a sulfur atom. The term "pharmaceutically acceptable salts, esters, amides and prodrugs" as used herein refers to those carboxylate salts, amino acid addition salts, esters, amides and prodrugs of the compounds of the present invention which are, within the scope of sound medical judgement, suitable for use in contact with with the tissues of humans and lower animals with undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, of the compounds of the invention. The term "salts" refers to the relatively non- toxic, inorganic and organic acid addition salts of compounds of the present invention. These salts can be prepared in situ during the final isolation and purification of the compounds or by separately reacting the purified compound in its free base form with a suitable organic or inorganic acid and isolating the salt thus formed. Representative salts include the hydrobromide, hydrochloride, sulfate, bisulfate, phosphate, nitrate, acetate, oxalate, valerate, oleate, palmitate, stearate, laurate, borate, benzoate, lactate, phosphate, tosylate, citrate, maleate, fumarate, succinate, tartrate, naphthylate, mesylate, glucoheptonate, lactiobionate and laurylsulphonate salts and the like. These may include cations based on the alkali and alkaline earth metals, such as sodium, lithium, potassium, calcium, magnesium and the like, as well as nontoxic ammonium, quaternary ammonium and amine cations including, but not limited to, ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine and the like. (See, for example S. M. Berge, et al., "Pharmaceutical Salts," J. Pharm. Sci.. 66: 1-19 (1977) which is incorporated herein by reference.) Examples of pharmaceutically acceptable, non-toxic esters of the compounds of this invention include Ci to C alkyl esters wherein the alkyl group is a straight or branched chain. Acceptable esters also include C5 to C 7 cycloalkyl esters as well as arylalkyl esters such as, but not limited to benzyl. Ci to C4 alkyl esters are preferred. Esters of the compounds of the present invention may be prepared according to conventional methods. Examples of pharmaceutically acceptable, non-toxic amides of the compounds of this invention include amides derived from ammonia, primary Ci to CQ alkyl amines and secondary Ci to C dialkyl amines wherein the alkyl groups are straight or branched chain. In the case of secondary amines the amine may also be in the form of a 5 or 6 membered heterocycle containing one nitrogen atom. Amides derived from ammonia, Ci to C 3 alkyl primary amides and Ci to C dialkyl secondary amides are preferred. Amides of the compounds of the invention may be prepared according to conventional methods. The term "prodrug" refers to compounds that are rapidly transformed in vivo to yield the parent compound of the above formula, for example by hydrolysis in blood. A thorough discussion is provided in T. Higuchi and V. Stella, "Pro-drugs as Novel Delivery Systems", Vol 14 of the A.C.S. Symposium Series, and in Bioreversible Carriers in Drug Design, ed. Edward B. Roche, American Pharmaceutical Association and Pergamon Press, 1987, both of which are incorporated herein by reference. Where appropriate, prodrugs of derivatives of compounds of the present invention may be prepared by any suitable method. For those compounds in which the prodrug moiety is an amino acid or peptide functionality, the condensation of the amino group with amino acids and peptides may be effected in accordance with conventional condensation methods such as the azide method, the mixed acid anhydride method, the DCC (dicyclohexylcarbodiimede) method, the active ester method (p-nitrophenyl ester method, N-hydroxysuccinic acid imide ester method, cyanomethyl ester method and the like), the Woodward reagent K method, the DCC- HOBT (1-hydroxy-benzotriazole) method and the like. Classical methods for amino acid condensation reactions are described in "Peptide Synthesis" Second Edition, M. Bodansky, Y.S. Klausner and M.A. Ondetti (1976). As in conventional peptide sysnthesϊs, branched chain amino and carboxyl groups at alpha and omega positions in amino acids may be protected and deprotected if necessary. The protecting groups for amino groups which can be used involve, for example, benzyloxycarbonyl (Z), o-chlorobenzyloxycarbonyl ((2-Cl)Z)), p-nitrobenzyloxycarbonyl (Z(Nθ2)), p-methoxybenzyloxycarbonyl (Z(OMe)), t-amyloxycarbonyl (Aoc), isobomealoxycarbonyl, adamantyloxycarbonyl (Adoc), 2-(4-biphenyl)-2-propyloxy carbonyl (Bpoc), 9-fluorenyl-methoxycarbonyl (Fmoc), methylsulfonylethoxy carbonyl (Msc), trifluoroacetyl, phthalyl, formyl, 2-nitrophenylsulfonyl (Nps), diphenylphosphinothioyl (Ppt) and dimemylphosphino-thioyl (Mpt). The examples for protecting groups for carboxyl groups involve, for example, benzyl ester (OBzl), cyclohexyl ester, 4-nitrobenzyl ester (OBzlNθ2), t-butyl ester (OtBu), 4- pyridylmethyl ester (OPic) and the like. In the course of the synthesis of certain of the compounds of the present invention, specific amino acids having functional groups other than amino and carboxyl groups in the branched chain such as arginine, cysteine, serine and the like may be protected, if necessary, with suitable protecting groups. It is preferable that, for example, the guanidino group (NG) in arginine may be protected with nitro, p-toluenesulfonyl (Tos), benzyloxycarbonyl (Z), adamantyloxycarbonyl (Adoc), p-methoxybenzenesulfonyl, 4-methoxy-2,6-dimethyl- benzenesulfonyl (Mts) and the like; the thiol group in cysteine may be protected with benzyl, p- methoxybenzyl, triphenylmethyl, acetomidomethyl, ethylcarbamyl, 4-methylbenzyl (4-MeBzl), 2,4,6-trimethylbenzyl (T b) and the like; and the hydroxy group in serine may be protected with benzyl (Bzl), t-butyl, acetyl, tetrahydropyranyl (THP) and the like. Numerous asymmetric centers may exist in the compounds of the present invention. Except where otherwise noted, the present invention contemplates the various stereoisomers and mixtures thereof. Accordingly, whenever a bond is represented by a wavy line, it is intended that both steric orientations are intended. The compounds of the invention, including but not limited to those specified in the examples, possess immunomodulatory activity in animals. As immunosuppressants, the compounds are expected to be useful in the treatment and/or prevention of rejection of transplanted organs or tissues, such as kidney, heart, lung, bone marrow, skin or cornea transplants, and also in the treatment or prevention of autoimmune, inflammatory, proliferative, and hyperproliferative diseases, such as rheumatoid arthritis, lupus erythematosus, sytemic lupus erythematosus, multiple sclerosis, myasthenia gravis, type I diabetes, uveitis, Hashimoto's thyroiditis, nephrotic syndrome, psoriasis, atopical dermatitis, contact dermatitis, seborrheic dermatitis, graft-versus-host diseases by medulla ossium transplantation, vernal keratocojunctivitis, eczematous dermatises, lichen planu, pemphigus, bullous pemphigoid, epidermolysis bullosa, urticaria, angioedemas, vasculitides, erythemas, cutaneous eosinophilias, alopecia areata and the like. The compounds of this invention are also expected to find use in the treatment of reversible obstructive airways disease. Further, the compounds of this invention may be indicated in the treatment of diseases caused by intestinal inflammations and allergies, such as Coeliac disease, gastroenteritis, mastocytosis, Crohn's disease, ulcerative colitis, and the like; and food-related allergic diseases which have symptoms remote from the gastrointestinal tract, as for example migraine, rhinitis, and eczema. Additionally, some compounds appear to possess FK-506 antagonistic properties. The compounds of the present invention may thus be used in the treatment of immunodepression or a disorder involving immunodepression. Examples of disorders involving immunodepression include AIDS, cancer, senile dementia, trauma (including wound healing, surgery and shock) chronic bacterial infection, and certain central nervous system disorders. The immunodepression to be treated may be caused by an overdose of an immunosuppressive macrocyclic compound, for example derivatives of 12-(2-cyclohexyl-l-methylvinyl)-13, 19,21,27-tetramethyl-ll,28-dioxa-4-azatricyclo[22.3.1.0 4 > 9 ] octacos-18-ene such as FR- 900506, or rapamycin. Overdosing of such medicants by patients is quite common upon their realizing that they have forgotten to take their medication at the prescribed time and can lead to serious side effects. A further situation in which the compounds of the present invention may be used to treat immunosuppression is in vaccination. It is sometimes found that the antigen introduced into the body for the acquisition of immunity from disease acts as an immunosuppressive agent, and so antibodies are not produced by the body and immunity is not acquired. By introducing a compound of the invention into the body (as in a vaccine), the undesired immunosuppression may be overcome and immunity acquired. Aqueous liquid compositions of the present invention may be particularly useful for the treatment and prevention of various diseases of the eye such as autoimmune diseases (including, for example, conical cornea, keratitis, dysophia epithelialis corneae, leukoma, Mooren's ulcer, sclevitis and Graves' ophthalmopathy) and rejection of corneal transplantation. When used in the above or other treatments, a therapeutically effective amount of one of the compounds of the present invention may be employed in pure form or, where such forms exist, in pharmaceutically acceptable salt, ester or prodrug form. Alternatively, the compound may be administered as pharmaceutical compositions containing the compound of interest in combination with one or more pharmaceutically acceptable excipients. By a "therapeutically effective amount" of the compound of the invention is meant a sufficient amount of the compound to treat gastrointestinal disorders, at a reasonable benefit risk ratio applicable to any medical treatment. It will be understood, however, that the total daily usage of the compounds and compositions of the present invention will be decided by the attending physician within the scope of sound medical judgement. The specific therapeutically effective dose level for any particular patient will depend upon a variety of factors including the disorder being treated and the severity of the disorder; activity of the specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drags used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts. For example, it is well within the skill of the art to start doses of the compound at levels lower than required for to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved. The total daily dose of the compounds of this invention administered to a human or lower animal may range from about 0.001 to about 3 mg/kg/day. For purposes of oral administration, more preferable doses may be in the range of from about 0.005 to about 1.5 mg/kg/day. If desired, the effective daily dose may be divided into multiple doses for purposes of administration; consequently, single dose compositions may contain such amounts or submultiples thereof to make up the daily dose. The pharmaceutical compositions of the present invention comprise a compound of the invention and a pharmaceutically acceptable carrier or excipient, which may be administered orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, or as an oral or nasal spray. By "pharmaceutically acceptable carrier" is meant a non-toxic solid, semi-solid or liquid filler, diluent, encapsulating material or formulation auxiliary of any type. The term "parenteral" as used herein refers to modes of administration which include intravenous, intramuscular, intraperitoneal, intrastemal, subcutaneous and intraarticular injection and infusion. Pharmaceutical compositions of this invention for parenteral injection comprise pharmaceutically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions as well as sterile powders for reconstitution into sterile injectable solutions or dispersions just prior to use. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), carboxymethylcellulose and suitable mixtures thereof, vegetable oils (such as olive oil), and injectable organic esters such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. These compositions may also contain adjuvants such as preservative, wetting agents, emulsifying agents, and dispersing agents. Prevention of the action of microorganisms may be ensured by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents such as sugars, sodium chloride, and the like, Prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin. In some cases, in order to prolong the effect of the drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of aparenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle. Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides) Depot injectable formulations are also prepared by entrapping the drug in liposomes ormicroemulsions which are compatible with body tissues. The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use. Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents. Solid compositions of a similar type may also be employed as fillers in soft and hard- filled gelatin capsules using such, excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes. The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above-mentioned excipients. Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethyl formamide, oils (in particular, cottonseed, groundnut, com, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents. Suspensions, in addition to the active compounds, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar, and tragacanth, and mixtures thereof. Topical administration includes administration to the skin or mucosa, including surfaces of the lung and eye. Compositions for topical administration, including those for inhalation, may be prepared as a dry powder which may be pressurized or non-pressurized. In non- pressurized powder compositions, the active ingredient in finely divided form may be used in admixture with a larger-sized pharmaceutically acceptable inert carrier comprising particles having a size, for example, of up to 100 micrometers in diameter. Suitable inert carriers include sugars such as lactose. Desirably, at least 95% by weight of the particles of the active ingredient have an effective particle size in the range of 0.01 to 10 micrometers. Alternatively, the composition may be pressurized and contain a compressed gas, such as nitrogen or a liquified gas propellant The liquified propellant medium and indeed the total composition is preferably such that the active ingredient does not dissolve therein to any substantial extent. The pressurized composition may also contain a surface active agent. The surface active agent may be a liquid or solid non-ionic surface active agent or may be a solid anionic surface active agent. It is preferred to use the solid anionic surface active agent in the form of a sodium salt. A further form of topical administration is to the eye, as for the treatment of immune- mediated conditions of the eye such as automimmue diseases, allergic or inflammatory conditions, and corneal transplants. The compound of the invention is delivered in a pharmaceutically acceptable ophthalmic vehicle, such that the compound is maintained in contact with the ocular surface for a sufficient time period to allow the compound to penetrate the corneal and internal regions of the eye, as for example the anterior chamber, posterior chamber, vitreous body, aqueous humor, vitreous humor, cornea, iris cilary, lens, choroid retina and sclera. The pharmaceutically acceptable ophthalmic vehicle may, for example, be an ointment, vegetable oil or an encapsulating material. Compositions for rectal or vaginal aαministration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable non-irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at room temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound. Compounds of the present invention can also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multi-lamellar hydrated liquid crystals that are dispersed in an aqueous medium. Any non-toxic, physiologically acceptable and metabolizable lipid capable of forming liposomes can be used. The present compositions in liposome form can contain, in addition to a compound of the present invention, stabilizers, preservatives, excipients, and the like. The preferred lipids are the phospholipids and the phosphatidyl cholines Qecithins), both natural and synthetic. Methods to form liposomes are known in the art. See, for example, Prescott, Ed., Methods in Cell Biology. Volume XTV, Academic Press, New York, N.Y. (1976), p. 33 et seq. The compounds of the invention may be prepared using one or more of the processes which follow. The starting materials for use in these processes are preferably one of the macrolides isolated from culture media obtained in accordance with known methods by fermentation of microorganisms of the genus Streptomyces. which are disclosed in European Patent Application No.0184162. Samples are available from the Fermentation Research Institute, Tsukuba, Ibaraki 305, Japan under the provisions of the Budapest Treaty, under deposit No. FERM BP-927. This strain has been redeposited on April 27, 1989 with the Agricultural Research Culture Collection International Depository, Peoria, Illinois 61604, USA under the provisions of the Budapest Treaty, under deposit No. NRRL 18488. The macrolide FR-900520 (European Patent Application 0184162), also known as ascomycin, may be prepared in accordance to the published methods of (i) H. Hatanaka, M. Iwami, T. Kino, T. Goto and M. Okuhara, FR-900520 and FR-900523, Novel immunosuppressants isolated from A streptomyces. I. Taxonomy of the producing strain. J. Antibiot., 1988. XLI(ll), 1586- 1591; (ii) H. Hatanaka, T. Kino, S. Miyata, N. Inamura, A. Kuroda, T. Goto, H. Tanaka and M. Okuhara, FR-900520 and FR-900523, Novel immunosuppressants isolated from A streptomyces. II. Fermentation, isolation and physico-chemical and biological characteristics. Antibiot, 1988. XLI(ll), 1592-1601; (iii) T. Arai, Y. Koyama, T. Suenaga and H. Honda, Ascomycin, An Antifungal Antibiotic. J. Antibiot., 1962. 15(231-2); and (iv) T. Arai in U.S. Patent No. 3,244,592. One or more of the processes discussed below may be then employed to produce the desired compound of the invention. Such processes comprises: (a) producing a compound of formulae I-Vπi, which contains a CH-OR group, by selective activation of a selected CH-OH group in a corresponding compound wherein -OR is a leaving group which is easily displaced by nucleophilic attack. (b) producing a compound of formulae I- VIII, which contains a CH-N3 group, by selective displacement of an -OR group in a corresponding compound. (c) producing a compound of formulae I-Vm, which contains a CH-NH group, by selective reduction of a CH-N3 group in a corresponding compound. (d) producing a compound of formulae I- VIE, which contains a CH-NHCOR group, by selective acylation of a CH-NH group in a corresponding compound wherein R is selected from hydrogen, aryl, arylalkyl, alkyl, heterocyclic, heterocyclic alkyl, cycloalkyl, and cycloalkylalkyl. (e) producing a compound of formulae I-VHI, which contains a CH-NRιR 2 group, by selective alkylation of a CH-NH 2 group in a corresponding compound wherein Ri and R 2 are independently selected from hydrogen, aryl, arylalkyl, alkyl, heterocyclic, heterocyclic alkyl, cycloalkyl, and cycloalkylalkyl. (f) producing a compound of formulae I-VJTI, which contains a CH-NHC(=X)NH-R group, by selective urea or thiourea formation from a CH-NH 2 group in a corresponding compound wherein R is selected from hydrogen, aryl, arylalkyl, alkyl, heterocyclic, heterocyclic alkyl, cycloalkyl, and cycloalkylalkyl, and X is oxygen or sulfur. (g) producing a compound of formulae I- VIE, which contains a CH-NH-SC^R group, by selective sulfonylation of a CH-NH group in a corresponding compound wherein R is selected from aryl, arylalkyl, alkyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl and heterocyclic. (h) producing a compound of formulae I-VTfl, which contains a CH-NH-C(=0)OR group, by selective carbamate formation from a selected CH-NH 2 group in a corresponding compound wherein R is selected from aryl, cycloalkyl, cycloalkyl alkyl, alkyl, heterocyclic alkyl, heterocyclic and arylalkyl. (i) producing a compound of formulae I- VIII, which contains a CH-NH-C(=NH)NH 2 group, by selective guanidinium formation from a CH-NH 2 group in a corresponding compound. (j) producing a compound of formulae I-VIII, which contains a CH-NH-SR group, by selective sulfenylation of a CH-NH group in a correspondmg compound wherein R is selected from aryl, arylalkyl, alkyl, cycloalkyl, cycloalkylalkyl, heterocyclic alkyl and heterocyclic. (k) producing a compound of formulae I-VHI, which contains a CH-X group, by selective halogenation of a CH-OH group in a corresponding compound wherein X is selected from chlorine, bromine, fluorine and iodine. (I) producing a compound of formulae I-VJTI, which contains a CH-P(0)(OR) 2 group, by selective phosphonic acid ester formation of a CH-X group in a corresponding compound wherein R is selected from alkyl, arylalkyl, and aryl. (m) producing a compound of formulae I- VIE, which contains a CH-0-P(0)(OR) 2 group, by selective phosphorylation of a CH-OH group in a corresponding compound wherein Ris selected from alkyl, arylalkyl, and aryl. (n) producing a compound of formulae I-VEI, which contains a CH-S-R group, by selective thioether formation from a CH-OH group in a corresponding compound wherein R is selected from cycloalkyl, cycloalkyl alkyl, heterocyclic, heterocylic alkyl, alkyl, arylalkyl, and aryl. (o) producing a compound of formulae I-VEI, which contains a CH-0-C(=S)-OR group, by selective aryl- or alkyloxythiocarbonylation of a CH-OH group in a corresponding compound wherein R is selected from cycloalkyl, cycloalkyl alkyl, heterocyclic, heterocylic alkyl, alkyl, arylalkyl, and aryl. (p) producing a compound of formulae I-VEI, which contains one or more CH-O-R groups, by selective ether formation of one or more CH-OH groups in a corresponding compound wherein R is selected from cycloalkyl, cycloalkyl alkyl, heterocyclic, heterocylic alkyl, alkyl, arylalkyl, aryl, lower alkoxycarbonylalkyl, arylalkoxycarbonylalkyl, and arylalkylcarbonylalkyl. (q) producing a compound of formulae I-VIE, which contains a CH- (substitoted)phthalimide group, by selective cyclic imide formation using a CH-NH 2 group in a corresponding compound. (r) producing a compound of formulae I-VEI, which contains a CH-NH-P(=Y)R 2 group, by selective phosphinamide formation from a CH-NH group in a corresponding compound wherein R is phenyl, or substituted phenyl and Y is oxygen or sulfur. (s) producing a compound of formulae I-VEI, which contains CH-N-P(=Y)(OR) 2 group, by selective phosphoramide formation from a CH-NH 2 group in a corresponding compound wherein R is phenyl, arylalkyl, or substituted phenyl and Y is oxygen or sulfur. (t) producing a compound of formulae I-VTE, which contains a CH 2 group, by selective deoxygenation of a CH-0-C(=S)-OR group in a corresponding compound. (u) producing a compound of formulae I-VEt, which contains a C(OH)=CH-C(=0) or a C(=0)-CH 2 -C(=0) group, by selective oxidation of a CH(OH)-CH -C(=0) group in a corresponding compound. (v) producing a compound of formulae I-VEI, which contains a C(=0)-CRιR 2 -C(=0) group, by selective alkylation of a C(OH)=CH-C(=0) or a C(=0)-CH 2 -C(=0) group in a corresponding compound wherein Ri and R are independently selected from hydrogen, aryl, cycloalkyl, cycloalkyl alkyl, alkyl, heterocyclic alkyl, heterocyclic and arylalkyl, but both cannot be hydrogen. (w) producing a compound of formulae I-VEI, which contains a C(=0)-CRιR 2 -C(=0) group, by selective halogenation of a C(OH)=CH-C(=0) or a C(=0)-CH 2 -C(=0) group in a corresponding compound wherein Ri and R 2 are independently selected from fluorine, chlorine, bromine and iodine. (x) producing a compound of formulae I-VEI, which contains a C(=0)-CH(OH)- C(=0) group, by selective oxidation of a C(OH)=CH-C(=0) or a C(=0)-CH -C(=0) group in a corresponding compound. (z) producing a compound of formulae I-VEI, which contains a C(=0)-C(N 2 )-C(=0) group, by selective diazotization of a C(OH)=CH-C(=0) or a C(=0)-CH 2 -C(=0) group in a corresponding compound. (aa) producing a compound of formulae I-VEI, which contains a C(=CH-R)-CH - C(=0) group, by selective olefination of a C(OH)=CH-C(=0) or a C(=0)-CH 2 -C(=0) group in a corresponding compound wherein R is selected from lower alkyl and arylalkyl. (bb) producing a compound of formulae I-VEI, which contains a C(OCOR)=CH- C(=0) group, by selective O-acylation of a C(ΟH)=CH-C(=0) or a C(=0)-CH 2 -C(=0) group in a corresponding compound wherein R is selected from aryl, cycloalkyl, cycloalkyl alkyl, alkyl, heterocyclic alkyl, heterocyclic and arylalkyl. (cc) producing a compound of formulae I- VIE, which contains a C(NH-R)=CH- C(=0) group, by selective amination of a C(ΟH)=CH-C(=0) or a C(=0)-CH 2 -C(=0) group in a corresponding compound wherein R is selected from alkylamine, arylalkylamine, arylamine and amino acid derivatives. (dd) producing a compound of formulae I- VIE, which contains C(0)-C(=CH-R)- C(=0) group, by selective alkylidene formation of a C(ΟH)=CH-C(=0) or a C(=0)-CH - C(=0) group in a corresponding compound wherein R is selected from hydrogen, aryl, cycloalkyl, cycloalkyl alkyl, alkyl, heterocyclic alkyl, heterocyclic and arylalkyl. (ee) producing a compound of formulae I-VEI, which contains a carbon-carbon double bond, by elimination of HL from a corresponding compound, where L is a leaving group. (ff) producing a compound of formulae I- VIE, which contains a quinoxaline, benzoquinoxaline, pyrazino[2,3-d]pyridazine, pyrido[3,4-b]pyrazine, or a pteridine by condensation of a 1,2-dicarbonyl or masked 1,2-dicarbonyl groups of a corresponding compound with an appropriate aromatic diamine. (gg) producing a compound of formulae I-VEI, which contains one or more hydroxyl groups, by selective reduction of one or more C=0 groups of a corresponding compound. (hh) producing a compound of formulae I-VEI, which contains one dihydro- benzo[l,5]thiazepine, by reaction of an alpha,beta-unsaturated ketone of a corresponding compound with an appropriate 2-aminothiophenol. (ii) producing a compound of formulae I-VIE, which contains one or more carbonyl groups, by selective oxidation of one or more hydroxyl groups of a corresponding compound. (jj) producing a compound of formulae I-VEI, by selective reaction of one of the carbonyl groups of a corresponding compound and dithiols. (kk) producing a compound of formulae I-VEI, which contains an oxime group, by selective reaction of one of the carbonyl groups of a corresponding compound with hydroxyl amine or O-alkylated hydroxyl amines. (11) producing a compound of formulae I-VIE, which contains a yrazole system, by condensation of a 1,3-dϊcarbonyl group of a corresponding compound and appropriate hydrazines. (mm) producing a compound of formulae I-VIE, which contains a substituted pyrimidine system, by condensation of the 1,3-dicarbonyl group of a corresponding compound with appropriate amidines, guanidines, isoureas, ureas and thioureas. (nn) producing a compound of formulae I-VEI, which contains afiiran system, by reaction of the 1,3-dicarbonyl group of a corresponding compound with appropriate diazoacetic esters or diazomethyl ketones. (oo) producing a compound of formulae I-VEI, which contains an isoxazole system, by condensation of the 1,3-dicarbonyl group of a corresponding compound with hydroxyl amine. (pp) producing a compound of formulae I-VEI, which contains a yridine system, by condensation of the 1,3-dicarbonyl group of a corresponding compound with appropriate malonic acid derivatives or cyanoacetic acid derivatives. (qq) producing a compound of formulae I-VIE, which contains a benzo[l,5]thiazepine, benzo[l,5]oxazepine or benzo[l,5]diazepine system, by condensation of the 1,3-dicarbonyl group of a corresponding compound with appropriate 2-aminothiophenols, 2-aminophenols, and 1,2-aromatic diamines. (rr) producing a compound of formulae I-VEI, which contains a keto-substituted furan system, by reaction of the 1,3-dicarbonyl group of a corresponding compound with appropriate aldehydes, and enol ethers. (ss) producing a compound of formulae I-VEI, which contains a substituted phenyl group, by C-arylation of a 1,3-dicarbonyl group of a corresponding compound with appropriate l-halo-2-nitro-aromatics. (uu) producing a compounds of formulae I-VEI, which contains a 2-isoxazoline, by nitrile oxide 1,3-dipolar cycloaddition to an enone. (zz) producing a compound of formulae I-VIE, which contain either a beta-hydroxy ketone or an alpha,beta-enone, by reductive hydrolysis of a corresponding 2-isoxazoline and subsequent separation of the two compounds. (eee) producing a compound of formulae I-VEI, which contains a hydrazone, by selective hydrazone formation with a corresponding ketone. (fff) producing a compound of formulae I-VIE, which contains either an alpha- hydroxy, beta-keto acid or ester, by selective nucleophilic addition and subsequent benziϋc acid type rearrangement of a corresponding compound containing a tricarbonyl moiety. (ggg) producing a compound of formulae I-VEI, which contains a 1,2-dicarbonyl system, by selective oxidative cleavage of a benzilic acid rearrangement product which has been derived from a corresponding compound. (hhh) producing a compound of formulae I-VIE, which contains an allylic alcohol, by selective reduction of a corresponding enone. (iii) producing a compound of formulae I-VEI, which contains an epoxide, by selective addition of the carbene arising from diazomethane across an activated carbonyl. (jjj) producing a compound of formulae I-VIE, which contains a carboxylic acid, by selective ester cleavage in a corresponding compound. (kkk) producing a compound of formulae I-VIE, which contains a substituted or unsubstituted carboxamide, by selective condensation of the corresponding amine with a corresponding carboxylic acid. Gil) producing a compound of formulae I-VEI, which contains a 24R-hydroxyl substituent, by selective inversion of the naturally occurring 24S configuration. (mmm) producing a compound of formulae I-VIE, which contains an alkyloxycarbonyl hydrazone, by selective condensation of an alkyl carbazate with a corresponding compound of formulae I-VEI, having a ketone. (nnn) producing a compound of formulae I-VEI, which contains a C-33-alkylcarbonyl or polyhaloalkylcarbonyl substituent, by selective C-acylation of 32-oxo-ascomycin or a related analog. (ooo) producing a compound of formulae I-VEI, which contains a 33-diazo moiety, by selective diazotization of a derivative of 32-oxo-ascomycin or a related analog. (ppp) producing a compound of formulae I-VIE, which contains one thiazole, by condensation of an alpha substituted carbonyl or an alpha substituted masked carbonyl group of a corresponding compound with an appropriate thioamide, thiourea or with dithiocarbamic acid derivatives, where the alpha substituent L is a leaving group. (qqq) producing a compound of formulae I-VTE, which contains one imidazole, by condensation of an alpha substituted carbonyl or an alpha substituted masked carbonyl group of a corresponding compound with an appropriate amidine, isourea or guanidine, where the substituent L is a leaving group. (rrr) producing a compound of formulae I-VEI, which contains one oxazole, by condensation of an alpha substituted carbonyl or an alpha substituted masked carbonyl group of a corresponding compound with an appropriate amide, where the substiment L is a leaving group. (sss) producing a compound of formulae I-VEI, which contains a tertiary alcohol, by selective addition of a Grignard reagent or an organometallic reagent to a carbonyl moiety of a corresponding compound. (ttt) producing a compound of formulae I-VEI, which contains one pyrrole, by cyclization of an appropriate gamma-amino alpha hydroxy carbonyl or a masked garmna-amino alpha hydroxy carbonyl of a corresponding compound prepared by process (sss). (uuu) producing a compound of formulae I-VIE, which contains one pyrazine, by condensation of a 1,2-dicarbonyl or masked 1,2-dicarbonyl group of a corresponding compound with an appropriate 1,2-diamine in the presence of an oxidizing agent (vw) producing a compound of formulae I-VEI, which contains one pyridine, by condensation of a 1,5-dicarbonyl group prepared by process (sss) of a corresponding compound with ammonia. (www) producing a compound of formulae I-VEI, which contains one pyridazine, by condensation of a 1,4-dicarbonyl group prepared by process (sss) of a corresponding compound with hydrazine. (xxx) producing a compound of formulae I-VTE, which contains a 1,2-thiocarbonate, by reacting a 1,2-diol of a corresponding compound with thiocarbonyldiimidazole or an appropriately activated thiocarbonate. (yyy) producing a compound of formulae I-VEI, which contains a 1,2-carbonate, by reacting a 1,2-diol of a corresponding compound with carbonyldiimidazole, triphosgene, phosgene or an appropriately activated carbonate. (zzz) producing a compound of formulae I-VDT, which contains a 1,2-phosphonate group, by reacting a 1,2-diol of a corresponding compound with an appropriate alkoxyphosphonyl dichloride. (aaaa) producing a compound of formulae I-VEI, which contains an olefin, by reduction of a 1,2-thiocarbonate prepared by process (xxx) of a corresponding compound. (bbbb) producing a compound of formulae I-VIE, which contains a CH 2 group, by selective reduction of a 1,2-dicarbonyl or masked 1,2-dicarbonyl group of a corresponding compound. (cccc) producing a compound of formulae I-VEI, which contains an indole group, by selective reduction and condensation of a 2-(o-nitrophenyl)-l,3-diketone [prepared by process (ss)] of a corresponding compound. (dddd) producing a compound of formulae I-VEI, which contains a substituted triazole group, by cycloaddition of a CH-N 3 group in a corresponding compound with appropriate acetylene analogues. (eeee) producing a compound of formulae I-VIE, which contains a substituted pyrrole group, by reaction of a CH-NH group in a corresponding compound with appropriate dicarbonyl compounds. (ffff) producing a compound of formulae I-VEI, which contains one ethanalyl group, first by selective oxidation of the double bond of an allyl group to a vicinal diol, followed by oxidative cleavage of the diol in a corresponding compound, (gggg) producing a compound of formulae I-VIE, which contains one carboxymethyl group, by selective oxidation of an ethanalyl group in a corresponding compound, (hhhh) producing a compound of formulae I-VIE, which contains one alkyl carboxymethyl group, by esterification of a carboxymethyl group in a corresponding compound, (iiii) producing a compound of formulae I-VEI, which contains one cyclopropylmethyl group, by selective cyclopropanation of the double bond of an allyl group in a corresponding compound, (jjjj) producing a compound of formulae I-VEI, which contains one pyrrole, by reaction of a 1,4-dicarbonyl group with amines in a corresponding compound, (kkkk) producing a compound of formulae I-VEI, which contains one furan, by cyclization of a 1,4-dicarbonyl group in a corresponding compound, (1111) producing a compound of formulae I-VEI, which contains one methyl ketone, by selective oxidation of the double bond of an allyl group in a corresponding compound, (mmmm) producing a compound of formulae I-VIE, which contains a cyano group by Beckmann fragmentation of an oxime derivative of an alpha-methoxy cyclohexanone in a corresponding compound, (nnnn) producing a compound of formulae I-VEI, which contains a hydrazide, by reduction of the corresponding hydrazone, (0000) producing a compound of formulae I-VIE, which contains an amine, by reduction of the corresponding oxime, (pppp) producing a compound of formulae I-VEI, which contains an alpha,beta- saturated ketone, by reduction of the corresponding alpha,beta-unsaturated enone, (qqqq) producing a compound of formulae I-VIE, which contains an isoxazoline, by treatment of a beta-hydroxy oxime with a dehydrating reagent, (rrrr) producing a compound of formulae I-VIE, which contains an beta-hydroxy carbonyl, by treatment of a carbonyl with a base in the presence of another carbonyl moiety, (ssss) producing a compound of formulae I-VIE, which contains a cyclic inline, by treatment of an enone system with a glycine imine in the presence of base resulting in first Michael addition at the beta-carbon and subsequent imine formation upon aqueous workup, (tttt) producing a compound of formulae I-VEI, which contains a substituted pyrrole, by treatment of an enone with a glycine imine in the presence of an appropriate catalyst to induce a 1,3-dipolar cycloaddition, (uuuu) producing a compound of formulae I-VIE, which contains a beta-keto carbox¬ ylic acid, ester or amide, by decomposition with light or heat of an alpha diazoketone, and (vvw) producing a compound of formulae I-VTE which contains a ketone, a product of decarboxylation of a beta-keto carboxylic acid, by heating. In process (a), suitable reagents for activation of an alcohol include acetic anhydride, trifluoromeώanesulfonic anhydride (triflic anhydride), methanesulfonyl chloride (mesyl chloride), p-toluenesulfonyl chloride (tosyl chloride), trifluoroacetic anhydride, trifluoroacetyl chloride, methoxysulfonyl fluoride (magic methyl), o-nitrobenzenesulfonyl chloride, 1-methyl- 2-fluoropyridinium salt and the like. The activation may be carried out in a solvent which does not adversely affect the reaction (e.g., diethylether, dichloromethane, tetrahydrofuran, chloroform or N,N- dimethylformamide or a mixture thereof). The reaction may require cooling or heating, depending on the activation method chosen. Further, the reaction is preferably conducted in the presence of an organic or inorganic base such as an alkaline earth metal (e.g. calcium, etc.), alkali metal hydride (e.g. sodium hydride, etc.), alkali metal hydroxide (e.g. sodium hydroxide, potassium hydroxide, etc.), alkali metal carbonate (e.g. sodium carbonate, potassium carbonate, etc.), alkali metal hydrogen carbonate (e.g. sodium hydrogen carbonate, potassium hydrogen carbonate, etc.), alkali metal alkoxide (e.g. sodium methoxide, sodium ethoxide, potassium tert-butoxide, etc.), alkali metal alkanoic acid (e.g. sodium acetate, etc.), trialkylamine (e.g. triethylamine, etc.), pyridine compounds (e.g. pyridine, lutidine, picoline, 4-N,N-djmethylaminopyridine, etc.), quinoline, and the like, preferably in the presence of organic bases such as triethylamine or pyridine. The activation may also be carried out using a starting material having an opposite configuration at a carbon center. In this situation, the following two additional steps are required to yield a starting material having an epimeric hydroxyl moiety, i.e. (1) the alcohol is oxidized to its corresponding ketone, (2) the obtained ketone is reduced under selective conditions. Both chiral centers having either [R]- or [S]-configuration can be obtained selectively and separately. In process (b), suitable azide reagents include well-established alkali metal azides such as sodium or lithium azides (NaN3 or LiN3) in the presence or absence of crown ethers, more reactive tetraalkylammonium azides (Danishefski, S. J.; DeNinno, M. P.; Chen, S.-H. J. Am. Chem. Soc. 1988, 110, 3929), a copper-assisted azide reaction (Yamamoto, Y.; Asao, N. J. Org. Chem. 1990, 55, 5303) and a hydrogen azide-amine system (Saito, S.; Yokoyama, H.; Ishikawa, T.; Niwa, N.; Moriwake, T. Tetrahedron Lett. 1991, 32, 663; Saito, S.; Takahashi, N.; Ishikawa, T.; Moriwake, T. Tetrahedron Lett. 1991, 32, 667). The azide displacement reaction may be carried out in a solvent which does not adversely affect the reaction (e.g. chloroform, dichloromethane, tetrahydrofuran, pyridine, dimethylsulfoxide, N,N-dimethylformamide, hexamethylphosphoramide, etc. or a mixture thereof)- The reaction may be conducted above, at, or below ambient temperature. In process (c), the reduction may be carried out catalytically using hydrogen. Suitable catalysts include, but are not limited to platinum catalysts (e.g. platinum oxide, platinum black), palladium catalysts (e.g. palladium oxide, palladium on charcoal, palladium black, palladium hydroxide on charcoal, palladium on calcium carbonate poisoned with lead, palladium on barium carbonate with quinoline), nickel catalysts (e.g. nickel oxide, Raney nickel), rhodium catalysts (e.g. rhodium on alumina). Reduction may also be carried out using metal reducing reagents (see Review; Scriven, E. F. V.; Turnbull, K. Chem Rev. 1988, 88, 321; Patai, S., Ed., "The Chemistry of the Azido Group," Interscience Publishers, New York, 1971; Scriven, E. F. V., Ed., "Azides and Nitrenes Reactivity and Utility," Academic Press, Inc., New York, 1984) such as sodium borohydride under phase-transfer conditions, borohydride supported on an ion exchange resin, lithium aluminum hydride and the like, furthermore, 1,3-propanedithiol-triethylamine method (Bay ley, H; Staudring, D. N.; Knowles, J. R. Tetrahedron Lett. 1978, 3633), triphenylphosphine (Vaultier, M.; Knouzi, N.; Carrie, R. Tetrahedron Lett. 1983, 24, 763), and sodium tellurium hydride (Suzuki, H; Takaoka, K. Chem Lett. 1984, 1733). The reduction may be carried out in a solvent which does not adversely affect the reaction (e.g., alcohols, water, acetone, dichloromethane, tetrahydrofuran, pyridine or N,N- dimethylformamide or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (d), suitable N-acylations may be carried out using the methods of symmetric carboxylic acid anhydrides, carboxylic acid halides, mixed carbonic-carboxylic anhydrides, active esters (p-nitrophenylester, trichlorophenyl ester, pentafluorophenyl ester, N-hydroxysuccinimide, cyanoethyl and the like), and carboxylic acid with suitable condensing reagents such as DCC (N,N-dicyclohexylcarbodiimide and its related condensing agents), DCC-HOBt (N V-dicyclohexylcarbodiimide-1-hydroxybenzotriazole), Woodward reagent K method, N,N-carbonyldiimidazole and phosphonium containing reagents (e.g. benzotriazolyloxytris[dimetiιylamino]phosphonium hexafluorophosphate, N,N-bis[2-oxo-3- ox-azolidinyl]phosphorodiamidic chloride, diethylphosphorobromidate, diphenylphosphoryl azide, bromo tris[dimemylamino]phosphonium hexafluorophosphate, and the like). Suitable reagents for amide formation include, but are not limited to formyl derivatives, acetyl halides (chloroacetyl, trichloroacetyl, σ-nitrophenylacetyl, o-nitrophenoxyacetyl, acetoacetyl, [N- dithiobenzyloxycarbonylamino]acetyl and the like), and substituted propionyl derivatives (3-phenylpropionyl, isobutyryl, picolinoyl, and the like). Other groups may be found in volume 3 of The Peptides Gross, E. and Meinhofer, J. Academic Press, 1981 and Protective Groups in Organic Synthesis Greene, T. W. John Wiley & Sons, New York, Chapter 7, 1981. Typically used coupling conditions are described by Gross, E.; Meinhofer, J. "The Peptides" vol. 3, Academic Press, 1981. The N-acylation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, chloroform, tetrahydrofuran, NN-dimeti yiTormamide, dimethylsulfoxide, diethylether, and the like, or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (e), N-alkylations may be carried out using aldehydes or ketones-followed by reduction of the initially formed iminium ion {The following reagents can be used for the reduction; sodium cyanoborohydride-boron trifluoride or the reducing reagents cited in process (c)}, corresponding halides in the presence of bases listed in process (a), or lithium dialkyl cuprate (King, F. E.; King, T. J.; Muir, I. H. M. /. Chem. Soc. 1946, 5; Yamamoto, H.; Maruoka, K. /. Org. Chem. 1980, 45, 2739). Suitable reagents for N-alkylation include, but are not limited to benzyl halide, 3,4-dimethoxybenzyl halide, nitrobenzyl halide, di(p- methoxyphenyl)methyl halide, triphenylmethyl halide, and the like. Other groups may be found in volume 3 of The Peptides, Gross, E. and Meinhofer, J. Academic Press, 1981 and Protective Groups in Organic Synthesis, Greene, T. W. John Wiley & Sons, New York, Chapter 7, 1981. The N-alkylation may be carried out in a solvent which does not adversely affect the reaction (e.g., acetone, dichloromethane, tetrahydrofuran, pyridine orNN- dimethylformamide or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (f), urea formation may be carried out from the following reactions; reaction with silicon tetraisocyanate or silicon tetraisothiocyanate (Neville, R. G.; McGee, J. J. Can. J. Chem. 1963, 41, 2123), reaction with NN-carbonyldiimidazole or N,N- tMcicarbonyldiimidazole, followed by N-substituted primary or secondary amines or ammonia (Staab, H. A.; Wendel, K. Org. Synth. 1968, 48, 44), and reaction with phosgene or thiophosgene in the presence of rert-amine, followed by N-substituted primary or secondary amines or ammonia. The ureido formation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, toluene, dichloromethane, tetrahydrofuran, pyridine, N,N-dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (g), N-sulfonylation may be carried out using substituted sulfonylhalides in the presence of suitable rt-amines such as trialkylamine, pyridine, and the like (Remers, W. A.; Roth, R. H; Gibs, G. J.; Weiss, M. J. J. Org. Chem. 1971, 36, 1232). Suitable reagents include, but are not limited to benzenesulfonyl halide, p-methyoxybenzenesulfonyl halide, 2,4,6-trimethylbenzenesulfonyl halide, toluenesulfonyl halide, benzylsulfonyl halide, p- methoxybenzylsulfonyl halide, trifluoromethylsulfonyl halide, phenacylsulfonyl halide, and the like. Some other representative groups may be found in volume 3 of The Peptides, Gross, E. and Meinhofer, J. Academic Press, 1981 and Protective Groups in Organic Synthesis, Greene, T. W. John Wiley & Sons, New York, Chapter 7, 1981. The N-aryl- or alkylsulfonylation may be carried out in a solvent which does not adversely affect the reaction (e.g., acetone, dichloromethane, tetrahydrofuran, pyridine or N,N-dimethylformamide or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (h), N-carbamate formations may be carried out using common protecting groups for amino group such as, but not limited to methylcarbamates (cyclopropylmethyl, 9- fluόrenylmethyl, and the like), substituted ethylcarbamates (2,2,2-trichloroethyl, 2- phosphonoethyl, 2-methylthioethyl, and the like), substituted propyl and isopropylcarbamates (1,1-dimethylpropynyl, 1 -methyl- l-(4-biphenylyl)ethyl, tert-butyl, phenyl, p-nitrobenzyl, 8- quinolyl, N-hydroxypiperidinyl, benzyl, dimethoxybenzyl, 9-anthrylmethyl, 1-adamantyl, cyclohexyl, t -amyl, cinnamoyl, isobutyl, N'-p-phenylaminothiocarbonyl, N'- piperidinylcarbonyl, diphenylmethyl, and the like). Preparations of N-carbamates and other groups may be found in volume 3 of The Peptides, Gross, E. and Meinhofer, J. Academic Press, 1981 and Protective Groups in Organic Synthesis, Greene, T. W. John Wiley & Sons, New York, Chapter 7, 1981. The N-carbamate formation may be carried out in a solvent which does not adversely affect the reaction (e.g., acetone, dichloromethane, tetrahydrofuran, pyridine or N,N-dimethylf ormamide or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (i), N-guanidium formation may be carried out using several common reagents such as l-guanyl-3,5-dimethylpyrazole (Salvadori, S.; Sarto, G. P.; Tomatis, R. Eur. J. Med. Chem. Chim. Ther. 1983, 18, 489), O-methylisourea (Van Νispen, J. W.; Tesser, G. L; Νivard, R. J. F. Int. J. Peptide Protein Res. 1977, 9, 193), and thiourea sulfonylate (Maryanoff, C. A.; Stanzione, R. C; Plampin, J. Ν.; Mills, J. E. /. Org. Chem. 1986, 57, 1882). The N-guanidinium formation may be carried out in a solvent which does not adversely affect the reaction (e.g., acetone, dichloromethane, tetrahydrofuran, pyridine or N,N- dimethylformamide or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (j), N-sulfenamides may be prepared from an amine and a sulfenyl halide (Davis, F. A.; Nadir, U. K. Org. Prep. Proc. Int. 1979, 11, 33; Kobayashi, T.; lino, K.; Hiraoka, T. J. Am. Chem. Soc. 1977, 99, 5505; Zervas, L.; Borovas, D.; Gazis, E. /. Am. Chem. Soc. 1963, 85, 3660). Suitable reagents include, but are not limited to benzenesulfenyl halide, o-nitrobenzenesulfenyl halide, 2,4-dinitrosulfenyl halide, pentachlorobenzenesulfenyl halide, 2-nitro-4-methoxybenzenesulfenyl halide, triphenylmethylsulfenyl halide, and the like. Other groups may be found in volume 3 of The Peptides, Gross, E. and Meinhofer, J. Academic Press, 1981 and Protective Groups in Organic Synthesis, Greene, T. W. John Wiley & Sons, New York, Chapter 7, 1981. The N-sulfenylation may be carried out in a solvent which does not adversely affect the reaction (e.g., acetone, dichloromethane, tetrahydrofuran, pyridine or N,N-dimethylformamide or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (k), suitable halogenation reagents include, but are not limited to triphenylphosphine with halogens (Verheyden, J. P. H.; Moffatt, J. G. /. Am. Chem. Soc. 1964, 86, 2093; Bergman, R. G. ibid., 1969, 91, 7405; Hrubiec, R. T.; Smith, M. B. /. Org. Chem., 1983, 48, 3667), triphenylphosphine with cyanogen halides (Homer, L.; Oediger, H.; Hoffmann, H. Annalen Chem. 1959, 626, 26), triphenylphosphine with carbon tetrahalides (Hooz, J.; Gilani, S. S. H. Can. J. Chem. 1968, 46, 86; Chem. Commun. 1968, 1350), triphenylphosphine with ΝBS (N-bromosuccinimide)(Schweizer, E. E.; Creasy, W. S.; Light, K. K.; Shaffer, E. T. J. Org. Chem. 1969, 34, 212), and triphenylphosphine with hexachloroacetone (Magid, R. M.; Stanley-Fmchey, O.; Johnson, W. L. Tetrahedron Lett. Wll, 2999; Magnid, R. M.; Stanley-Fmchey, O.; Johnson, W. L.; Allen, T. G. J. Org. Chem.1979, 44, 359). The halogenation may also be accomplished by other reagents such as mono- or tri-alkylsilyl halides with or without sodium halides (Olah, G. A.; Husain, A.; Singh, B. P.; Mehrota, A. K. /. Org. Chem. 1983, 48, 3667; Balme, G.; Fournet, G.; Gore, J. Tetrahedron Lett. 1986, 27, 1907), polymer bound trimethylsilyl derivatives (Cainelli, G.; Contento, M.; Manescalchi, F.; Plessi, L.; Panunzio, M. Synthesis 1983, 306; Imamoto, T.; Matsumoto, T.; Kusumoto, T.; Yokoyama, M. Synthesis 1983, 460), N,N-dichlorophosphoramidic dichloride (Chem Lett. 1978, 923), phosphorus trihalide-zinc halide (Anderson, Jr. A. G.; Owen, Ν. E. T.; Freenor, F. J.; Erickson, D. Synthesis 1976, 398), diethylaminosulfur trifluoride (Middleton, W. J. J. Org. Chem. 1975, 40, 574), triphenoxyphosphonium alkyl halide (Rydon, H. Ν. Org. Synth. 1971, 51, 44; Verheyden, J. P. H.; Moffatt, J. G. J. Org. Chem. 1972, 37, 2289), and the like. The halogenation may be carried out in a solvent which does not adversely affect the reaction (e.g., acetone, dichloromethane, tetrahydrofuran, pyridine or N,N-dimethylformamide or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (1), phosphonic acid ester formation may be carried out using Michaelis- Arbuzov reactions (Bhattacharya, A. K.; Thyagarajan, G. Chem. Rev. 1981, 81, 415; Bauer, G.; Haegele, G. Angew. Chem. Int. Ed. Engl. 1977, 16, All). The phosphonic acid ester formation may be carried out in a solvent which does not adversely affect the reaction (e.g., acetone, dichloromethane, tetrahydrofuran, pyridine or N,N-dimethylformamide or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (m), phosphorylation may be carried out using, but is not limited to the 2- halo-2-oxo- 1, 3, 2-dioxaphospholane- triethylamine reaction (Chandrarakumar, Ν. S.; Hajdu, J. J. Org. Chem. 1983, 48, 1197). The phosphorylation may be carried out in a solvent which does not adversely affect the reaction (e.g., benzene, toluene, acetone, dichloromethane, tetrahydrofuran or N,N-dimethylformamide or a mixture thereof). Further, the reaction is preferably conducted in the presence of organic or inorganic bases, as described in process (a), preferably in the presence of organic bases such as triethylamine, pyridine etc. The reaction may be conducted above, at, or below ambient temperature, more preferably from 0 to 50 °C. In process (n), thioether formation may be carried out using, but is not limited to aryl- or alkylmercaptan in the presence of suitable t -amines such as trialkylamine, pyridine, and the like. The reaction may also be carried out by a metal-catalyzed thioether formation (Guindon, Y; Frenette, R; Fortin, R.; Rokach, J. J. Org. Chem. 1983, 48, 1357), alkali metal salts of aryl- or alkylmercaptans with a compound of formulae I-VIE which contains CH-OR group (OR is the leaving group). The alkali metal may be selected from sodium, potassium, lithium, and cesium. The thioether formation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, N,N- dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (o), aryl- or alkyloxythiocarbonylation may be carried out using aryl- or alkyloxythiocarbonylchloride or corresponding halides in the presence of suitable tert-amines such as trialkylamine, pyridine, and the like. The aryl- or alkylthiocarbonylation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, NN-dimethylfoimamide etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (p), ether formation may be carried out using, but is not limited to aryl-, arylalkyl-, or alkylhalides in the presence of KY- zeolite (Onaka, M.; Kawai, M.; Izumi, Y. Chem. Lett. 1983, 1101), polymeric materials (Kimura, Y.; Kirszensztejn, P.; Regen, S. L. J. Org. Chem. 1983, 48, 385), nickel-catalysis (Camps, F.; Coll, J.; Moreto, J. M. Synthesis 1982, 186; Yamashita. Synthesis 1977, 803), arylalkyl-O-p-toluenesulfonate (Dewick, P. M. Synth. Commun. 1981, 11, 853), potassium or sodium alkoxides (Bates, R. B.; Janda, K. D. J. Org. Chem. 1982, 47, 4374), pyridine or other bases (Chem Lett. 1978, 57), tetraalkylammonium halide (Miller, J. M.; So, K. H.; Clark, J. H. Can. J. Chem. 1979, 1887), mercury perchlorate (McKillop, A.; Ford, M. E. Tetrahedron 1974, 30, 2461), or a phase transfer catalyst (McKillop, A.; Fiaud, J.-C; Hug, R. P. Tetrahedron 1974, 30, 1379). The ether formation may also be carried out with dialkyl- or diarylphosphoric acid in the presence of p-toluenesulfonic acid (Kashman, Y. /. Org. Chem. 1972, 37, 912), or with diazo compounds withtinCQ) chloride (Christensen, L. F.; Broom, A. D. /. Org. Chem. 1972, 37, 3398). The ether formation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, N,N- dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. More specifically, 0-alkylation may be carried out using bromoacetic acid derivatives, iodoacetic acid derivatives, trifluoromethanesulfonyloxy acetic acid derivatives and the like in the presence of an appropriate base such as triethylamine. The reaction is performed in an inert solvent such as Ν,Ν-dimethylformamide or dichloromethane preferably between -50 °C and 80 °C. Alternatively, alkylation can be carried out using alkyl diazoacetates in the presence of a metal catalyst, for example Rh(OAc) 2 in an inert solvent such as dichloromethane preferably between -20 °C and 80 °C. In process (q), N-cyclic imide formations may be carried out using phthalic anhydride (Sasaki, T.; Minamoto, K.; Itoh, H. /. Org. Chem. 1978, 43, 232Q), o- methoxycarbonylbenzoyl chloride with trialkylamine (Hoogwater, D. A.; Reinhoudt, D. Ν.; Lie, T. S.; Gunneweg, J. J.; Beyerman, H. C. Reel. Trav. Chim. Pays-Bas. 1973, 92, 819), orN-ethoxycarbonylphthalimide (Νefkens, G. H. L.; Tesser, G. I.; Νivard, R. J. F. Reel. Trav. Chim Pays-Bas. 1960, 79, 688). Other groups and reagents may be found in volume 3 of The Peptides, Gross, E. and Meinhofer, J. Academic Press, 1981 and Protective Groups in Organic Synthesis, Greene, T. W. John Wiley & Sons, New York, Chapter 1, 1981. The N-cyclic imide formation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, NN-dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. process (r), N-phosphinamide formation may be carried out using, but is not limited to phosphinyl chloride with N-methylmorpholine (Kenner, G. W.; Moore, G. A.; Ramage, R. Tetrahedron Lett. 1976, 3623). Suitable reagents include, but are not limited to diphenylphosphinyl chloride, dimethyl- or diphenyli iophosphϊnyl chloride, dibenzyl- or diphenylphosphinyl chloride. Other groups and conditions may be found in volume 3 of The Peptides, Gross, E. and Meinhofer, J. Academic Press, 1981 and Protective Groups in Organic Synthesis, Greene, T. W. John Wiley & Sons, New York, Chapter 7, 1981. The N- phosphinamide formation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, NN-dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (s), N-phosphoramide formation may be carried out using, but is not limited to diphenylphosphoryl chloride with a tert-amine-base (Adams, E.; Davis, Ν. C; Smith, E. L. J. Biol Chem. 1952, 199, 845), and triethylbenzylammonium chloride (Zwierzak, A. Synthesis 1975, 507; Zwierzak, A.; Piotrowicz, J. B. Angew. Chem. Int. Ed. Engl. 1977, 16, 107). Suitable reagents include, but are not limited to diphenylphosphoryl chloride, dimethyl- or diphenylthiophosphoryl chloride, dibenzyl- or diphenylphosphoryl chloride. Other groups and conditions may be found in volume 3 of The Peptides, Gross, E. and Meinhofer, J. Academic Press, 1981 and Protective Groups in Organic Synthesis, Greene, T. W. John Wiley & Sons, New York, Chapter 7, 1981. The N-phosphinamide formation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, N,N-dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (t), deoxygenation may be carried out using, but is not limited to phenoxythiocarbonyl derivative with tributyltin hydride and 2,2-azobis-2-methylpropionitrile (AIBΝ) (Robins, M. J.; Wilson, J. S.; Hansske, F. J. Am. Chem. Soc. 1983, 105, 4059; Barton, D. H. R.; McCombie, S. W. J. Chem Soc, Perkin Trans.l 1975, 1574), or a phenyldithiocarbonyl derivative with tributyltin hydride and AEBΝ (Hayashi, T.; Iwaoka, T.; Takeda, Ν.; Ohki, E. Chem. Pharm. Bull. 1978, 26, 1786). The deoxygenation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, N,N-dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (u), suitable oxidizing reagents include activated dialkyl sulfoxides (e.g. dimethylsulfoxide, methylethylsulfoxide) (Mancuso, A. J.; Swem, D. Synthesis 1981, 165), organo chromates [e.g. pyridinium chlorochromate (Corey, E. J.; Suggs, J. W. Tetrahedron Lett. 1975, 2647; Corey, E. J.; Boger, D. L. Tetrahedron Lett. 1978, 2461), pyridinium dichromate (Corey, E. J.; Schmidt, G. Tetrahedron Lett. 1979, 5, 399), Collins reagent (Collins, J. C; Hess, W. W.; Frank, F. J. Tetrahedron Lett. 1968, 3363)], tettapropylammonium perrathenate (Griffith, W. P.; Ley, S. V.; Whitcombe, G. P.; White, A. D. Chem Commun. 1987, 1625; Griffith, W. P. Aldrichimica Acta. 1990, 23, 13), and the like. The oxidation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, N,N-dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (v), sxiitable alkylating reagents include, but are not limited to aldehydes and ketones in the presence of reducing agents (Hrubowchak, D. M.; Smith, F. X. Tetrahedron Lett. 1983, 24, 4951), alkyl-, aryl, or arylalkyl halides (Shono, T.; Kashimura, S.; Sawamura, M.; Soejima, T. J. Org. Chem. 1988, 53, 907). hi the case that the reaction is conducted in the presence of an organic or inorganic bases such as an alkaline earth metal (e.g. calcium, balium, magnesium, thallium etc.), an alkali metal hydride (e.g. sodium hydride, lithium hydride, etc.), an alkali metal hydroxide (e.g. sodium hydroxide, potassium hydroxide, etc.), an alkali metal carbonate (e.g. sodium carbonate, potassium carbonate, etc.), an alkali metal hydrogen carbonate (e.g. sodium hydrogen carbonate, potassium hydrogen carbonate, etc.), an alkali metal alkoxide (e.g. sodium methoxide, sodium ethoxide, thallium ethoxide, potassium tert-butoxide, etc.), an alkali metal alkanoic acid (e.g. sodium acetate, etc.), a triaHtylamine (e.g. triethylamine, trimethylamine, etc.), or a pyridine compound (e.g. pyridine, lutidine, picoline, 4-N,N-dimethylaminopyridine, etc.), quinoline, and the like. The alkylation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, N,N-dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (w), suitable halogenation reagents include, but are not limited to halogens treated by irradiation (sun lamp) for several hours (Heffner, R.; Safaryn, J. E.; Joullie, M. M.; Tetrahedron Lett. 1987, 28, 6539) or oxalyl chloride (Evans, D. A.; Dow, R. L.; Shih, T. L.; Takecs, J. M.; Zahler, R. /. Am. Chem Soc. 1990, 112, 5290). The halogenation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, N,N-dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (x), suitable oxidation reagents include, but are not limited to oxodiperoxymolybdem.m( yridine)-l,3-dimet^ (Anderson, J. C; Smith, S. C. SYNLETT 1990, 2, 107) and oxodiperoxymolybdenum(pyridine)-hexamethylphosphoramide (Vedejs, E. /. Am. Chem Soc. 1974, 96, 5944; Vedejs, E.; Engler, D. A.; Telschow, J. E. /. Org. Chem. 1978, 43, 188). The oxidation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, N,N-dimethylformamide, etc., or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (z), a compound of formulae I-VEI may be treated with a diazotization reagent Suitable diazotization reagents include, but are not limited to azidotris(dieι ylamino)phosphoniιιm bromide (McGuiness, M.; Shechter, H. Tetrahedron Lett. 1990, 31, 4987), p-carboxybenzenesulfonyl azide (Hendrickson, R. G.; Wolf, W. A. /. Org. Chem. 1968, 33, 3610; Williams, M. A.; Miller, M. J. Tetrahedron Lett. 1990, 31, 1807), polymer bound p-toluenesulfonyl azide (Roush, W. R.; Feitler, D.; Rebek, J. Tetrahedron Lett. 1974, 1391), p-toluenesulfonyl azide (Regitz, M. Angew. Chem. 1967, 79, 786), 2- azo-3-ethylbenzthiazolium tettafluoroborate (Balli, H.; Kersting, F. Justus LiebigsAnn. Chem., 1961647, 1. Balli, H.; Low, R. Tetrahedron Lett. 1966, 5821), N,N- dimethylazidochloromethyleniminium chloride (Kokel, B.; Viehe, H. G. Angew. Chem Int. Ed. Engl. 1980, 19, 716; Kokel, B.; Boussouira, Ν. J. Heterocyclic Chem. 1987, 24, 1493), and mesyl azide (Danheiser, R. L.; Miller, R. F.; Brisbois, R. G.; Park, S. Z. J. Org. Chem. 1990, 55, 1959). The diazotization may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, NN- dimethylformamide, etc. or a mixture thereof). The reaction may be conducted above, at, or below ambient temperature. In process (aa), suitable olefination reagents include, but are not limited to Wittig reagents (Maecker, M., Org. React. 1965, 14, 270; Johnson, A. W., " Ylid Chemistry," Academic Press, New York, 1966) and CH 2 I 2 -Zn-TiCl4 [or Ti(NEt 2 )4] reagent (Hibino, J.; Okazoe, T.; Takai, K.; Nozaki, H. Tetrahedron Lett. 1985, 26, 5579; Okazoe, T.; Hibino, J.; Takai, K.; Nozaki, H. ibid. 1985, 26, 5581). The carbonyl olefination may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, NN-dimethylformamide, etc., or a mixture thereof). The reaction may be conducted at room temperature. In process (bb), suitable O-acylation reagents include, but are not limited to alkyl, aryl, or arylalkyl acyl halides (Lakhvich, F. A.; Khlebnicova, T. S.; Akhre , A. A. Synthesis 1985, 8, 784). The O-acylation may be carried out in a solvent which does not adversely affect the reaction (e.g. acetone, dichloromethane, tetrahydrofuran, pyridine, NN- dimethylformamide, etc., or a mixture thereof). The reaction may be conducted above, at or below ambient temperature. In process (cc), suitable amination reagents include, but are not limited to amino acid derivatives and lower alkyl, aryl, or arylalkyl amines (Winkler, J. D.; Hershberger, P. M.; Springer, J. P. Tetrahedron Lett. 1986, 27, 5177). The reaction may be carried out in refluxing in benzene, toluene or a solvent which does not adversely affect the reaction (e.g. tetrahydrofuran, pyridine, NN-dimethylformamide, etc., or a mixture thereof). The reaction may be conducted at room temperature. In process (dd), the alkylidene formation may be carried out using, but is not limited to aldehydes and ketones with active methylene compounds. (Schonberg, A.; Singer, E. Chem. Ber. 1970, 103, 3871; Chatterjee, S. J. Chem Soc. B, 1969, 725). The alkylidene formation may be carried out in a solvent which does not adversely affect the reaction (eg. acetone, dichloromethane, tetrahydrofuran, pyridine, NN-dimethylformamide, etc., or a mixture thereof). The reaction may be conducted under cooling to heating. In process (ee), Lmay be hydroxy, or a good leaving group (halogen, tosylate, mesylate or triflate, for example). When a precursor compound contains a C(OH)-CH 2 -C=0 group, the elimination of H 2 0 may be carried out in a solvent which is inert under the reaction conditions (e.g. toluene) with a trace of acid (e.g. toluene sulfonic acid), at a temperature selected from 50 to 100 °C. When the precursor compound contains a good leaving group, the eUmination may be carried out in the presence of a base (e.g. triethyl amine or potassium carbonate), at a temperature selected from 0 to 100 °C. In process (ft), suitable diamines include phenylene diamine and substituted 1,2-phenyl diamines, 2,3-diaminopyridine, 3,4-diaminopyridine, 4,5-diaminopyridazine, 4,5- diaminopyrimidϊne and their acid salts, preferably in the presence of tertiary amines (e.g. N- methylmorpholine). Suitable solvents include methanol, ethanol, propanol, acetonitrile, 2- butanone and NN-dimethylformamide, and a reaction temperature selected from 50 to 100 °C. In process (gg), suitable reagents include sodium borohydride, zinc in acetic acid, sodium triacetoxyborohydride in acetic acid, lithium trialkoxyaluminum hydride in tetrahydroftiran, potassium or lithium tti-sec-butylborohydride in tetrahydrofuran, and borane/t-butylamine complex in a solvent such as methanol or ethanol. The reduction may be conducted at -70 °C to room temperature. In process (hh), suitable 2-aminothiophenols include substituted 1,2-aminothiophenols, preferably in the presence of tertiary amine (e.g. N-methylmorpholine). Suitable solvents include methanol, ethanol and n-propanol; and the reaction may be conducted at a temperature selected from 50 to 100 * C. In process (ii), the reagent to be used in this reaction may include di(lower)alkyl sulfoxide (e.g. dimethyl sulfoxide, ethyl methyl sulfoxide, propyl methyl sulfoxide, isobutyl methyl sulfoxide, butyl methyl sulfoxide, isobutyl methyl sulfoxide, hexyl methyl sulfoxide, etc). This reaction is usually conducted in the presence of oxalyl chloride, acid chlorides, lower alkanoic anhydride such as acetic anhydride in a conventional solvent that does not adversely influence the reaction such as dichloromethane, acetone, ethyl acetate, tetrahydrofuran, pyridine, NN-dimethylformamide, etc., followed by the addition of a tertiary amine (e.g. triethyl amine). The reaction may be conducted at -70 °C to room temperature. In process (jj), the dithiols are lower alkyl dithiols (e.g. ethanedithiol, propanedithiol or butanedithiol) and 1,2-aryl dithiols (e.g. 1,2-benzenedithiol) in the presence of a Lewis acid (e.g. boron trifluoride etherate or lanthanum trichloride) in a conventional solvent that does not adversely influence the reaction such as dichloromethane, tetrahydrofuran or ether. The reaction may be conducted at -70 °C and room temperature. In process (kk), suitable oxygen-substituted amines include hydroxyl amine, O- alkylhydroxyl amines, and O-arylalkyl hydroxyl amines, for example O-benzyl hydroxyl amine. Suitable solvents include those that do not adversely affect the reaction, for example ethanol or methanol. The reaction is preferably carried out with one equivalent of hydroxyl amine, and at a temperature of 25 to 100 °C, more preferably at the reflux temperature of the solvent. In process (11), suitable hydrazines include alkylhydrazines (e.g. butylhydrazine), arylhydrazines (e.g. phenylhydrazine), acylhydrazines (e.g. acetylhydrazine), semicarbazides (e.g. t-butyloxycarbonyl hydrazine) and sulfonyl hydrazines (e.g. tosyl hydrazine) in a conventional solvent that does not adversely affect the reaction such as tetrahydrofuran, methanol or ethanol. The reaction may be conducted at 20 to 100 °C. In process (mm), 2-substitutions on the pyrimidine may be hydrogen, alkyl, aryl, hydroxyl, alkoxy, thiol, amino, alkylamino, arylamino, acylamino, carbamylamino, and sulphonylamino groups. The appropriate pyrimidine containing compounds may be prepared according to the methods described in " The Chemistry of Heterocyclic Compounds, Vol.16, supplement II, Chapter II, pp 21-60", D. J. Brown, John Wiley & Sons, 1985. In process (nn), the furan containing compounds may be prepared according to the method described by Paulissen, R., et. al. in Tetrahedron Lett. 1974, 607. In process (oo), one equivalent of hydroxyl amine hydrochloride and tertiary amine (e.g. N-methylmorpholine) in a conventional solvent that does not adversely affect the reaction such as tetrahydrofuran, methanol, ethanol or isopropanol is used to prepare the compound. The reaction is conducted at 20 to 100 °C. In process (pp), the pyridine containing compounds may be prepared according to the literature: Osman, A. Ν.; Ismail, M. M.; Barakat, M. A. Rev. Roum. Chim. 1986, 31, 615- 624; Ried W.; Meyer, A., Ber. Deutsch. Chem. Ges. 1957, 90, 2841; Troschutz, R.; Troschultz, J.; Sollhuberkretzer, M. Arch Pharm. 1985, 318, 777-781. In process (qq), a substituted 2-aminothiophenol, a 2-aminophenol or an aromatic 1,2- diamine is used in a conventional solvent that does not adversely affect the reaction such as tetrahydrofuran, ethanol, isopropanol, acetonitrile or NN-dimethylformamide. The reaction may be conducted at 20 to 100 °C. In process (rr), the keto-substituted furan containing compound may be prepared according to the literature: Williams, P. H. et al, J. Am. Chem. Soc. 1960, 82, 4883; E. J. Corey et al., Chem. Lett. 1987, 223. In process (ss), suitable l-halo-2-nitroaromatics may be substituted l-fluoro-2- nitrobenzene, o-fluoro-nitropyridines, or o-bromo-nitro-naphthalene, etc. The arylation may be carried out in a solvent which does not adversely affect the reaction (e.g. tetrahydrofuran, NN-dimethylformamide, dimethoxyethane, diglyme, etc.). The base used to generate the anion may be isopropyl magnesium chloride, hthium diisopropyl amine or sodium hydride. The reaction may be conducted at a temperature selected from -70 °C to l00 °C. In process (uu), a nitrile oxide may be formed either by oxidation of an aldoxime or dehydration of a nitro compound as described in the following references or literature cited therein: (1) Torssell, K. G. B. "Nitrile Oxides, Nitrones and Nittonates in Organic Synthesis"; VCH Publishers: New York, 1988, p 64; (2) Kim, J. N.; Ryu, E. K. Synthetic Communications 1990, 20, 1373; (3) Chow, Y. L.; Shy, Y. Y.; Bakker, B. H.; Pillay, K. S. Heterocycles 1989, 29, 2245. The nitrile oxide is placed in the presence of an alpha,beta- unsaturated enone in an inert solvent to yield an 2-isoxazolines. Any isomers may subsequently be chomatographically separated. In process (zz), an isoxazoline may be transformed to the Corresponding beta-hydroxy ketone using but is not limited to molybenum hexacarbonyl in wet acetonitrile according to: Baraldi, P. G.; Barco, A.; Benetti, S.; Manfredini, S.; Simoni, D. Synthesis 1987, 276. Alternatively, Ti 3+ may be employed to attain N-O bond cleavage: Das, N. B.; Torssell, K. B. G. Tetrahedron 1983, 39, 2227. Additionally, Raney-nickel may also selectively cleave the N-0 bond without reducing the imino functionality as described in the following reference and literature cited therein: Torssell, K. G. B. "Nitrile Oxides, Nittones and Nittonates in Organic Synthesis"; VCH Publishers: New York, 1988, p 16 and 290. During the course of this transformation, a significant amount of dehydration occurs to produce alpha-beta unsaturated enones which may be separated from the beta-hydroxy ketones. In process (eee) τ an aryl- or alkylsulfonyl hydrazone may be formed by treatment of a ketone with an aryl- or alkylsulfonyl hydrazide in the presence of an acid catalyst in a solvent suitable for the reaction such as methanol or ethanol at temperatures ranging from ambient to the reflux temperature of the solvent In process (fff), a benzilic acid rearrangement to yield an alpha-hydroxy acid may be initiated in a tricarbonyl system by treatment with a slight excess of a hydroxylic base in THF- water initially between 0 °C and room temperature. The temperature may be permitted to rise to room temperature during the course of the reaction. Other nucleophiles such as methanol are also for this type of transformation at temperatures from ambient to the reflux temperature. In process (ggg), an alpha-hydroxy acid may be oxidatively cleaved by treatment with lead tetraacetate in an inert solvent (e.g. benzene) to form a ketone. In process (hhh), an allylic alcohol may be produced by selective reduction of an alpha- beta unsaturated enone. This is accomplished with but not limited to sodium borohydride in the presence of ceriumQTf) chloride heptahydrate in a suitable solvent such as methanol at or nearO °C. In process (iii), an epoxide may be produced on the central carbonyl of a tricarbonyl moiety by but not limited to excess diazomethane as described in: Fisher, M. J.; Chow, K.; ViUalobos, A.; Danishefsky, S. J. J. Org. Chem 1991, 56, 2900-2907. In process (jjj), liberation of the ester to the acid may be achieved by the cleavage of a suitably substituted ester function. Such a functional group may be benzyl, 2,2,2- trichloroethyl, 9-fluorenylmethyl and the like. These are cleaved by methods well known to those skilled in the art. In process (kkk), condensation of an amine with the acid may be performed using the mixed or symmetrical anhydride of said acid, or an ester of the acid, preferably activated, such as the ester derived from hydroxybenzotriazole, or the corresponding acylcyanide, acylimidazole, or acylazide of the aforementioned acid. In process (111), selective protection of the 32-hydroxyl moiety may be achieved using one of a variety of trialkylsilyl groups. This then leaves exposed a lone secondary alcohol on C-24 for selective inversion, which may be accomplished by activation of the 24-hydroxy as a mesylate, tosylate, etc., followed by inversion with a suitable nucleophile such as water, benzoic acid, formic acid, etc. On the other hand inversion of the unactivated 24-hydroxy group may be achieved using well described Mitsunobu conditions. Liberation of the silyl ether and inverted C-24 acylated hydroxy (if carboxylic acids are used as the nucleophile) is accomplished using methods well known to those skilled in the art. Alternatively, inversion may be accomplished without protection of the 32-hydroxyl group if ascomycin, FK506, or similar compounds are treated with diethylaminosulfur trifluoride (DAST) in an inert solvent such as methylene chloride. In process (mmm), condensation of an alkyloxy or substituted alklyoxy carbonyl hydrazine with ascomycin, FK506, similar compounds, or a suitable derivative thereof wherein the C-22 is available as a reactive center, including but not limited to a carbonyl, is performed in an inert solvent such as methanol, ethanol, 2-propanol, etc., in the presence of a catalyst which may be an acid such as formic acid, p-toluenesulfonic acid, or camphorsulfonic acid. In process (nnn), acylation at C-33 of 32-oxo-ascomycin or a suitable derivative thereof can be achieved, but is not limited to the process outlined in Danheiser, R. L.; Miller, R. F.; Brisbois, R. G.; Park, S. Z. J. Org. Chem. 1990, 55, 1959-1964. In process (ooo), diazotization at C-33 of 32-oxo-ascomycin or a suitable derivative thereof can be achieved, but is not limited to the process outlined in Danheiser, R. L.; Miller, R. F.; Brisbois, R. G.; Park, S. Z. J. Org. Chem. 1990, 55, 1959-1964. In process (ppp), L may be a hydroxyl group, or a good leaving group (halogen, tosylate, nittobenzenesulfonate, mesylate or triflate, for example). The condensation may be carried out in a solvent which does not adversely affect the reaction (e.g. isopropanol, acetonitrile, dioxane, NN-dimethylformamide, tetrahydrofuran, etc.). The reaction may be carried out in the presence of base (e.g. triethylamine, 4- methylmorpholine or magnesium carbonate, etc.), at a temperature selected from 0 to 100 °C. The appropriate thiazole containing compound may be prepared according to Hantzsch's synthesis described by: Katritzky, A.R.; Rees, C.W. "Comprehensive Heterocyclic Chemistry"; Pergamon Press: Oxford, 1984, Vol. 6, Part 4B, p.294-299. In process (qqq), L may be a hydroxyl group, or a good leaving group (halogen, tosylate, nitrobenzenesulfonate, mesylate or triflate, for example). The condensation may be carried out in a solvent which does not adversely affect the reaction (e.g. isopropanol, t-butanol, acetonitrile, dioxane, NN-dimethylformamide, tetrahydrofuran, etc.). The reaction may be carried out in the presence of base (e.g. triethylamine, 4-methylmorpholine, potassium carbonate or magnesium carbonate, etc.), at a temperature selected from 0 to 100 °C. Suitable amidines include formamidine, alkylamidines, arylamidines and alkylisoureas. Suitable guanidines include N-arylguanidines, N-acylated guanidines and N-sulfonylated guanidines. In process (rrr), L may be a hydroxyl group, or a good leaving group (halogen, tosylate, nitrobenzenesulfonate, mesylate or triflate, for example). The condensation may be carried out in a solvent which does not adversely affect the reaction (e.g. isopropanol, t-butanol, acetonitrile, dioxane, NN-dimethylformamide, tetrahydrofuran, etc.). The reaction may be carried out in the presence of a base (e.g., triethylamine, 4-methylmorpholine, potassium carbonate or magnesium carbonate), at a temperature selected from 0 to 100 °C. The amides are primary amides such as formamide, alkylacylamides and arylacylamides. In process (sss), the organometallic reagent may be a Grignard reagent an alkyllithium, or an aryllithium reagents. The selective addition may be carried out in a solvent which does not adversely affect the reaction (e.g., hexanes, ether, tetrahydrofuran, dimethoxyethane or 2-methoxyethyl ether). The reaction may be carried out in the presence of cerium (Tfl) at a temperature selected from -100 °Cto 0 °C. In process (ttt), the gamma amino alpha hydroxy carbonyl or a masked gamma amino alpha hydroxy carbonyl of a corresponding compound prepared by process (sss) may have substitutions (e.g. alkyl, aryl groups, etc.) at the alpha and or beta positions. Furthermore, the amino group may have N-alkyl or aryl substitutions. The condensation may be carried out in a solvent which does not adversely affect the reaction (e.g. isopropanol, t-butanol, acetonitrile, dioxane, Ν,Ν-dimethylformamide, tetrahydrofuran, etc.). The reaction may be carried out in the presence of a base (e.g. triethylamine, 4-methylmorpholine, potassium carbonate or magnesium carbonate, etc.), at a temperature selected from 0 to 100 °C. In process (uuu), the reaction is generally carried out in two steps: first the condensation of an alpha diketone or a masked alpha diketone with an 1,2-diaminoalkane gives a dihydropyrazine. Once the dihydropyrazine has been prepared, it may be oxidized by air in the presence of Pd/C, Pt0 2 or other catalysts. Metal oxides (e.g. Mn0 or CuO) may also be used for the aromatization. The condensation and oxidation may be carried out in a solvent which does not adversely affect the reactions (e.g. isopropanol, acetonitrile, dioxane, benzene, toluene, etc.). The reaction may be carried out in the presence of drying agent such as magnesium sulfate or molecular sieves at a temperature selected from 0 °C to 100 °C. In process (vvv), a 1,5-dicarbonyl group or a masked 1,5-dicarbonyl group prepared by process (sss) may have substitutions (e.g. alkyl, aryl groups etc.) at the alpha and/or beta positions. The condensation may be carried out with anhydrous ammonia in a solvent which does not adversely affect the reactions (e.g. liquid ammonia, isopropanol, acetonitrile, dioxane, benzene, toluene, etc.). The reaction may be carried out at a temperature selected from -40 °C to 100 °C. In process (www), a 1,4-dicarbonyl group or a masked 1,4-dicarbonyl group prepared by process (sss) may have substitutions (e.g. alkyl, aryl groups, etc.) at the alpha position. The condensation and oxidation may be carried out with anhydrous hydrazine in a solvent which does not adversely affect the reactions (e.g. isopropanol, acetonitrile, dioxane, benzene, toluene, etc.). The reaction may be carried out in the presence of a drying agent such as magnesium sulfate or molecular sieves at a temperature selected from 0 °C to 100 °C. In process (xxx), the thiocarbonate formation may be carried out in a solvent which does not adversely affect the reactions (e.g. toluene, acetone, methylene chloride, tetrahydrofuran or pyridine, etc.). The reaction may be carried out in the presence of a base such as triethylamine, pyridine, dimethylaminopyridine and sodium carbonate at a temperature selected from 0 °C to 100 °C. The thiocarbonylating reagent may be 1,1'- tMocarbonyldiimidazole, l,l'-thiocarbonylbis(2-pyridone), thiophosgene, or O-phenylthiochloroformate. In process (yyy), the carbonate formation may be carried out in a solvent which does not adversely affect the reactions (e.g. toluene, acetone, butanone, methylene chloride, tetrahydrofuran or pyridine etc.). The reaction may be carried out in the presence of a base such as triethylamine, pyridine, dimethylaminopyridine and sodium carbonate at a temperature selected from 0 °C to 100 °C. The carbonylating reagent may be l,r-carbonyldϋmidazole, l,l'-carbonylbis(2- pyridone), phosgene, triphosgene, ethyl chloroformate, ethyl trichloroacetate, or o- phenylchloroformate. In process (zzz), the cyclic phosphonate formation may be carried out by first reacting a diol from a selected compound with phosphorous trichloride followed by the addition of an appropriate alcohol and amine. The alcohol used may be an alkyl alcohol, or an aryl alcohol. The amine used may be primary or secondary. Altematively, the cyclic phosphonate formation may be carried out by directly reacting the diol from a corresponding compound with an appropriate alkoxyphophoryl dichloride. The phosphonate formation may be carried out in a solvent which does not adversely affect the reactions (e.g. carbon tetrachlori.de, chloroform, methylene chloride, toluene, tetrahydrofuran, etc.). The reaction may be carried out in the presence of a base such as triethylamine, pyridine, dime ylaminopyridine, and sodium carbonate at a temperature selected from O °Cto lOO °C. In process (aaaa), the reduction of thiocarbonate may be carried out in a solvent which does not adversely affect the reactions (e.g., toluene or tetrahydrofuran) at a temperature selected from 0 °C to 100 °C. The reducing agent used may be trimethylphosphite, triethylphosphite, trialkylphosphite or tri-n-butyltin hydride. In process (bbbb), the reduction of a 1,2-dicarbonyl group of a corresponding compound may be carried out in a solvent which does not adversely affect the reactions (e.g., methanol, ethanol, ethanol, pyridine or NN-dimethylformamide). The reducing agents used may be tin amalgam, aluminum amalgam with hydrogen chloride in ethanol, or may be hydrogen sulfide in pyridine or NN-dimethylformamide. In process (cccc), the reduction and condensation of a 2-(o-nitrophenyl)-l,3-diketone of a corresponding compound may be carried in a solvent which does not adversely affect the reactions (e.g. ethanol, tetrahydrofuran, ethyl acetate or benzene, etc.). The reducing agents used may be hydrogen gas over Pd/C, or Pt/C, zinc dust with ammonium chloride, zinc dust with hydrochloric acid at a temperature selected from 0 °C to 100 °C. In process (dddd), triazole formation may be carried out using, but is not limited to an azide derivative with suitable acetylene analogues include diethylacetylene dicarboxylate, dimethylacetylene dicarboxylate, methyl cyanoacetylenecarboxylate, and the likes. The reaction may be conducted above, or below ambient temperature, more preferably from 0 to 50 °C. In process (eeee), pyrrole formation may be carried out using, but is not limited to amine compounds with 1,4-dicarbonyl analogues, such as acetbnylacetone, and the likes. Suitable solvents include methanol, ethanol, n-propanol, isopropanol, acetonitrile and N,N- dimemyJ ormamide. The reaction may be conducted above, or below ambient temperature, more preferably from 50 to 100 °C. In process (ffff), suitable reagents for vicinal hydroxylation include osmium tettaoxide, potassium permanganate, and iodine in conjunction with silver acetate. Osmium tetroxide is preferably used with a regenerating agent such as hydrogen peroxide, alkaline t-butyl hydroperoxide or N-methylmorpholine-N-oxide, and a solvent that does not adversely affect the reaction, for example diethyl ether or tetrahydrofuran. Potassium permanganate is preferably used in mild conditions, for example alkaline aqueous solution or suspensions. Co- solvents such as t-butanol or acetic acid may also be used. Iodine-silver acetate under 'wet' conditions yields ci-diols. Preferably, iodine is used in aqueous acetic acid in the presence of silver acetate. Iodine-silver acetate under 'dry' conditions yields trans-diols. Here, the initial reaction is carried out in the absence of water, and final hydrolysis yields the diol. In each case, the oxidation is preferably carried out at a temperature of 0 to 100 °C. Suitable reagents for the oxidative cleavage of the vicinal diol include lead tettaacetate, phenyliodoso acetate, periodic acid or sodium metaperiodate. Suitable solvents for the first two reagents include benzene and glacial acetic acid. The second two reagents are preferably used in aqueous solution. The reaction is preferably carried out at a temperamre of 0 to 100 °C. In process (gggg), suitable reagents for the oxidation of an aldehyde of the corresponding compound may include silver oxide, chromic acid and potassium permanganate. In the presence of a variety of catalysts, oxygen may also be used in converting an aldehyde to a carboxylic acid of a corresponding compound. The catalysts may be palladium or platinum oxide. The air oxidation may be carried out in a solvent which does not adversely affect tiie reaction (e.g., ethanol, water, acetonitrile, aqueous acetone or pyridine) at a temperature of 0 to 100 °C. In process (hhhh), esters of a corresponding carboxylic acid may be prepared under neutral conditions at room temperature by the reaction of the carboxylic acid with alcohols in the presence of molar amounts of activating reagents such as triphenyl phosphine and diethyl azodicarboxylate, carbodϋmides, N,N'-carbonyldiimidazole and l-methyl-2-halopyridinium iodide. Esters may also be formed by reacting the corresponding carboxylic acid with diazoalkanes in a solvent which does not adversely affect the reaciton (e.g., ether, tetrahydrofuran or methylene chloride) at a temperature of from 0 to 100 °C. In process (iiii), the cyclopropanation of the allyl group of a corresponding compound may be carried out with diazoalkanes in a solvent which does not adversely affect the reaction (e.g., ether, methylene chloride or tetrahydrofuran) in the presence of a catalyst such as palladium (E) acetate. The temperature of the reaction is of -15 to 5 °C. In process (jjjj), a pyrrole ring may be produced by reacting a 1,4-dicarbonyl group of a corresponding compound with ammonia, or a substituted amine such as benzylamine or 2- aminoethanol. Suitable solvents include those which do not adversely affect the reaction (e.g., methylene chloride, tetrahydrofuran or dioxane). The reaction is preferably carried out at a temperature of 0 to 100 °C. In process (kkkk), the cyclization of a 1,4-dicarbonyl group of a corresponding compound may be carried out in the presence of a catalytic amount of acid (e.g., acetic acid or arylsulfonic acid). The reaction may be carried out in a solvent which does not adversely affect the reaction (e.g., methylene chloride, ether, benzene or toluene). The reaction is preferably carried out at a temperature of 0 to 60 °C. In process (1111), suitable reagents include air, a palladium (E) halide (e.g. palladium (E) chloride), in conjunction with a cuprous halide (e.g. cupper (I) chloride). Suitable solvents include those that do not adversely affect the reaction (e.g. DMF and water). The reaction is preferably carried out at a temperature of 0 to 100 °C. In process (mmmm), the ketone of the alpha-methoxy cyclohexanone in a corresponding compound may be first converted to its oxime derivative with hydroxylamine. The derivatization is preferably carried out in a solvent which does not adversely affect the reaction (e.g., ethanol, isopropanol or tetrahydrofuran) at a temperature of 0 to 100 °C. The hydroxyl group of the oxime (=N-OH) may then be converted to a good leaving group (=N-OL) by reacting with an alkylsulfonyl chloride (e.g., methanesulfonyl chloride or trifluoromethanesulfonyl chloride), an arylsulfonyl chloride (e.g., bezenesulfbnyl chloride or toluenesulfonyl chloride), a carboxylic acid anhydride (e.g., trifluoroacetic anhydride), phosphorous pentachloride, thionyl chloride or N-methyl 2-fluoropyridinium iodide. The activation of oxime is preferably carried out in a solvent that does not adversely affect the reaction (e.g., tetrahydrofuran or methylene chloride) at a temperature of -20 to 50 °C. The activated oxime of a corresponding compound may then be fragmented in a protic solvent such as ethanol or lower alkyl alcohol at a temperamre of 0 to 100 °C. Altematively, in process (mmmm), the Beckmann fragmentation may be carried out by reacting the alpha-methoxycyclohexanone directly with an o-alkylsulfonyl hydroxylamine or an o-arylsulfonyl hydroxylamine. The reaction may be carried out in a protic solvent (e.g., ethanol, propanol or benzyl alcohol) at a temperature of 0 to 100 °C. In process (nnnn), suitable reducing agents include but are not limited to sodium cyanoborohydride, lithium aluminum hydride, borane-pyridine, or hydrogen in the presence of such catalysts as Raney nickel, platinum, platinum oxide, or palladium. An acidic environment may promote the reduction in some cases, and acids such as hydrochloric acid or p- toluenesulfonic acid may be added for this purpose. The reduction may be carried out in a solvent which does not adversely affect the reaction (e.g. ethanol, ethyl acetate). In process (oooo), reduction of an oxime to the corresponding amine may be accomplished with but not limited to hydrogenation with a suitable catalyst such as palladium on carbon in a solvent inert to the reaction conditions (e.g. ethanol) at temperatures ranging from 0 to 100 °C. In process (pppp), reduction of an enone to the corresponding saturated ketone may be accomplished with but not limited to hydrogenation with a suitable catalyst such as either palladium on carbon or rhodium on alumina in a solvent inert to the reaction conditions (e.g. methanol, ethanol, isopropanol, ethyl acetate) in a temperature range from -78 to 100 °C. In process (qqqq), isoxazoline formation is accomplished by but not limited to the following sets of reaction conditions involving a beta-hydroxy oxime. One possible method is to treat the beta-hydroxy oxime with Martin's sulfurane dehydrating reagent at or near room temperature in a solvent inert to the reaction conditions such as methylene chloride. Altematively, the beta-hydroxy oxime may be treated with p-toluenesulfonyl chloride in a solvent such as pyridine at temperatures ranging from 0 to 100 °C. In process (rrrr), an intramolecular aldol reaction is may be accomplished by but is not limited to treatment of a carbonyl with a base such as potassium or sodium hydride in a solvent which is inert to the reaction conditions (e.g. tetrahydrofuran or N,N-dimethylformamide) at a temperature range from -78 to 150 °C. In process (ssss), a cyclic imine may be formed by but is not limited to tteatment of an alpha,beta-unsaturated enone with the sodium enolate of a glycine ester imine in an inert solvent such as tetrahydrofuran in a temperamre range from -78 to 100 °C. Upon aqueous workup, the imine hydrolyzes and spontaneously cyclizes to form the cyclic imine. In process (tttt), a substituted pyrrole may be formed by but is not limited to a 1,3-dipolar cycloaddition between an alpha,beta-unsaturated enone with a glycine ester imine in the presence of a suitable catalyst such as lithium bromide and triethylamine in a solvent inert to the reaction conditions (e.g. tetrahydrofuran) at or near room temperature. In process (uuuu), alpha diazoketones can be decomposed by exposure to UV light or by heating. Wolff rearrangements often ensue yielding beta-keto carboxylic acids when ran in a solvent mixture containing water, beta-keto esters when run in a solvent containing an alcohol, or beta-keto amides when ran in a solvent containing ammonia, a primary or a secondary amine. Moreover, if a beta-keto carboxylic acid is formed, decarboxylation can occur spontaneously or by heating. The compounds, processes and uses of the present invention will be better understood in connection with the following examples, which are intended as an illustration of and not a limitation upon the scope of the invention. Both below and throughout the specification, it is intended that citations to the literature are expressly incorporated by reference. Exa ple la and lb: Formula I: R= ethyl: R'= H: n= 1 : 1= trifluoromethylsulfonyl (R Configuration) and Formula I: R= ethyl: R'= H: n= 1: Rl= N^ (S Configuration ' ). Example la: Ascomycin (4.748 g, 6 mmol) was dissolved in 60 mL of methylene chloride at 0 °C. Pyridine (4.85 mL, 60 mmol), followed by irifluoromethanesulfonic acid anhydride (1.514 mL, 9 mmol) were carefully added to the reaction mixture. It was stirred at 0 °C for 10 min and allowed to warm to room temperamre. After stirring for 2 hours, 40 mL of cold 10%-NaHCθ 3 aqueous solution was carefully added to the cooled reaction mixture. Ethyl acetate (50 mL x 3) was added to extract the compound. The combined organic layers were washed with brine, 10%-NaHCθ3, brine, 10 -KHSO4, brine and dried over anhydrous magnesium sulfate. After the solvent was removed, the C32-triflate was obtained in quantitative yield. Example lb: Formula I: R= ethyl; R= H; n= 1; R l = N3 (S Configuration). Example la was dissolved in 40 mL of chloroform, and a chloroform solution containing n-teteabutylammonium azide (14 mmol) (Hendrickson, J. B.; Judelson, D. A.; Chancellor, T. Synthesis 1984, 321) was added to the mixture and stirred at room temperamre for 30 min. The solvent was removed, and the crude product was purified by silica gel column chromatography, eluting with 0.5%-methanol in chloroform to yield 2.043 g of the title compound. A small amount (100 mg) was purified further by recrystallization (3 mL of ether-8 mL of n-hexane) to yield 61.8 mg for characterization: mp.153-154 C; MS (FAB) miz: M+K = 855; IR(KBr) 3490-3420, 2960, 2940, 2880, 2830, 2090, 1740, 1720, 1700, 1650, 1455, 1380, 1360, 1350, 1325, 1285, 1270, 1200, 1174, 1160, 1145, 1105, 1090, 1040, 1010 cm -1 . Example 2: Formula I: R= ethyl: R '= H: n= 1: Rl= Mfr (S Configuration). The product of Example lb (1.632 g, 2 mmol) was dissolved in 40 mL of methanol:ethyl acetate(l:l). Lindlar catalyst (palladium on calcium carbonate poisoned with lead)(816 mg) was added. It was hydrogenated at 1 hydrogen atmosphere for 4 days. The catalyst was removed by filtration, more Lindlar catalyst (816 mg) was added, and hydrogenation was carried out for one more day at which time TLC analysis showed complete reaction. The catalyst was filtered over diatomaceous earth, and the filtrate was then evaporated to dryness to yield 1.560 g of the title compound. The product (200 mg) was recrystallized from ethyl acetate (0.75 mL) in n- hexane (1 mL) and ether (7 mL) for characterization. Yield: 138.4 mg, mp.141-143 C; MS (FAB) miz: M+K = 829; IR(KBr) 3440, 2960, 2940, 2880, 2830, 1740, 1705, 1645, 1500, 1455, 1450, 1380, 1350, 1325, 1280, 1245, 1200, 1170, 1140, 1100, 1040, 1015 cm" 1 . Example 3: Formula I: R= ethyl: R'= H: n= 1: Rl= CfoCfOiS (S Configuration). The product of Example la (923 mg, 1 mmol) was dissolved in 3 mL of N,N- dimethylformamide (DMF), potassium thioacetate (571 mg, 5 mmol) was added, and the reaction was stirred at room temperamre for 5 hours. Ethyl acetate (30 mL) was added to the reaction mixture, and the organic layer was washed with brine, 10%-NaHCθ3, brine, 10%- KHSO4 and brine, and then dried over magnesium sulfate. Evaporation of the solvent gave 837 mg of crude product. This was purified twice by silica gel column chromatography, eluting with 0.5%-methanol in chloroform. Yield: 165 mg. MS (FAB) miz: M+K = 888; IR(KBr) 3440, 2960, 2930, 2880, 2820, 1740, 1690, 1645, 1455, 1450, 1380, 1355, 1325, 1280, 1245, 1195, 1170, 1160, 1140, 1105, 1035, 1020, 1010 cm- 1 . Example 4: Formula I: R= ethyl: R'= H: n= 1: Rl= CH^CfOINH CS Configuration). The resultant product from Example 2 (250 mg, 0.32 mmol) in 3 mL of pyridine at 0 °C was treated with acetyl chloride (27 mL, 0.38 mmol), and the mixture was stirred at 0 C for 30 minutes and at room temperamre overnight Ethyl acetate (25 mL) was added, and the organic layer was washed with 10%-KHSθ 4 , brine, 10%-NaHCθ 3 , brine, and then dried over magnesium sulfate. The crude product (234 mg) obtained was purified by silica gel column chromatography, eluting with 0.5-1.5% methanol in chloroform. Yield: 68.7 mg. MS (FAB) miz: M+K = 871; IR(KBr) 3430, 2960, 2940, 2870, 2820, 1735, 1705, 1645, 1520, 1450, 1375, 1350, 1320, 1280, 1260, 1245, 1195, 1170, 1160, 1135, 1100, 1085, 1035, 1020 cm- 1 , Example 5: Formula I: R= ethyl: R'= H: n= 1: Rl= CgHjCfC NH CS Configuration). The resultant product from Example 2 (250 mg, 0.32 mmol) was treated in the same fashion as mentioned in Example 4, except benzoyl chloride (44.1 mL, 0.30 mmol) was employed instead of acetyl chloride. After silica gel column chromatography, a white powder was obtained. Yield: 46.0 mg. MS (FAB) miz: M+K = 933; Et(KBr) 3440, 2960, 2940, 2880, 2830, 1740, 1720, 1705, 1645, 1575, 1515, 1480, 1450, 1445, 1375, 1360, 1345, 1320, 1280, 1260, 1245, 1195, 1170, 1160, 1140, 1100, 1090, 1035, 1020, 1010 cm' 1 . Example 6: Formula I: R= ethyl: R'= H: n= 1: Rl= CgHsSfO^NH (S Configuration). The resultant product from Example 2 (250 mg, 0.32 mmol) was treated in the same fashion as mentioned in Example 4, except benzenesulfonyl chloride (48.5 mL, 0.30 mmol) was employed instead of acetyl chloride. Yield: 84.6 mg. MS (FAB) miz: M+K = 969; IR(KBr) 3440, 2960, 2940, 2870, 2820, 1740, 1700, 1645, 1450, 1445, 1375, 1335, 1325, 1305, 1290, 1260, 1245, 1195, 1160, 1140, 1100, 1090, 1080, 1035, 1020, 1005 cm- 1 . Example 7: Formula IE: R= ethyl: R'= H: n= 1 : R21= H: R3 = H: R22= OH: R24= H: R25 and R3-6 taken together form an oxime. =NR 3 - 8 -where 2&= hydroxyl. Ascomycin (1.187 g, 1.5 mmol) was dissolved in 30 mL of ethanol. After pyridine (1.215 mL, 15 mmol) and hydroxylamine hydrochloride (1.043 g, 15 mmol) were added to the reaction mixture, it was gently refluxed for 4 hours. Ethanol was removed by evaporation, and 50 mL of chloroform was added to the residue. The chloroform layer was washed with water, 10%-KHSO4, water and dried over anhydrous magnesium sulfate. Evaporation to dryness yielded 1.175 g of the title compound. This was recrystallized from ethyl acetate (8 mL)- hexane (25 mL) to obtain 889 mg. MS (FAB) miz: M+K = 845, M+H = 807; IR(KBr) 3440, 2950, 2920, 2870, 2820, 1740, 1705, 1645, 1450, 1375, 1350, 1330, 1280, 1260, 1230, 1195, 1170, 1160, 1100, 1090, 1045, 1035, 1010 cm" 1 . Examples 8a and 8b: Formula I: R= ethyl: R'= H: n= 1: R-l= tert-butyldimethylsilyloxy (R Configuration) and Formula V: R= ethyl: R'= H: n= 1: Rl= tert-butyldimethylsilyloxy: R21= H: R22= H: R- 3 - and R^ 4 - taken together form an oxo group: R 3 -^ and R-36 taken together form an oxo gτς>μp. Example 8a: Ascomycin (1.582 g, 2 mmol) was dissolved in 30 mL of methylene chloride, and tert-butyldimethylsilyl chloride (362 mg, 2.4 mmol) and imidazole (272 mg, 4 mmol) were added. It was then stirred at room temperamre for 4 days. Saturated aqueous ammonium chloride solution (20 mL) was added, and the product was extracted with ethyl acetate (25 mL x 3). The ethyl acetate layers were combined, washed with brine, dried over anhydrous magnesium sulfate, filtered and evaporated to dryness to yield 2.11 g of title compound. Example 8b: To a -78 °C solution of oxalyl chloride (96 mL, 1.1 mmol) in 5 mL of methylene chloride was added a solution of dimethylsulfoxide (156 mL, 2.2 mmol) in 4 mL of methylene chloride and the mixture was stirred at -78 °C. After 30 min a solution of example 8a (453 mg, 0.5 mmol) in 5 mL of methylene chloride was added. The reaction was carried out at -78 °C for 1.5 hours with stirring and then triethylamine (696.9 mL, 5 mmol) was added. After stirring at -78 °C for 5 min, the mixture was then allowed to stand at room temperature for 30 min. The reaction mixture was partitioned between 40 mL of ethylacetate and 10 mL of 10%-KHSθ4 solution. The separated organic layer was washed with 10%-KHSθ4 (3 x), brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 438 mg of the crude title compound. This was purified by silica gel column chromatography, eluting with 2.5% ethyl acetate in chloroform. Yield: 225.8 mg. MS (FAB) miz: M+K = 942; IR(KBr) 3500, 3440, 2950, 2935, 2880, 2860, 2820, 1740, 1720, 1650, 1630, 1580, 1460,1445, 1380, 1360, 1325, 1280, 1250, 1220, 1195, 1170, 1135, 1105, 1090, 1040, 1030, 1005 cm" 1 . Example 9: Formula I: R= ethyl: R'= H: n= 1: Rl= iodo (S Configuration). Ascomycin (3.164 g, 4 mmol) was dissolved in 20 mL of N,N-dimethylformamide (DMF), and methyltriphenoxyphosphonium iodide (2.713 g, 6 mmol) was added. The reaction was carried out under a nitrogen atmosphere at room temperamre for 4 days. Approximately 100 mL of ethyl acetate was added to the reaction, and the organic mixmre, was washed with brine, water, brine, and dried over anhydrous magnesium sulfate. After filtration, the filtrate was evaporated to dryness, and the crude product obtained was purified by silica gel column chromatography, eluting with 10%-ethyl acetate in chloroform. Yield: 1.86 g. MS (FAB) miz: M+K = 940; IR(KBr) 3500, 2960, 2940, 2870, 2820, 1740, 1720, 1690, 1670, 1650, 1620, 1500, 1490, 1450, 1440, 1405, 1385, 1360, 1350, 1320, 1280, 1250, 1205, 1195, 1170, 1155, 1140, 1100, 1090, 1070, 1035, 1000 cπr 1 . Example 10: Formula VE: R= ethyl: R'= H: n= 1: Rl= iodo: R21 and R22- taken together form an oxo group: R22= iodo: R24= H: R 3 -! and R-23- taken together form a bond: R-22= H: R24= H: R-3-5 and R-36 taken together form an oxo group. The title compound was isolated as a by-product from the reaction described in Example 9. Yield: 166 mg. MS (FAB) miz: M+K = 1030, M-I = 866; IR(KBr) 3420, 2980, 2930, 2870, 2820, 1740, 1690, 1645, 1625, 1590, 1485, 1450, 1380, 1360, 1345, 1320, 1280, 1260, 1245, 1210, 1190, 1170, 1140, 1100, 1090, 1075, 1020, 1010 cm" 1 . Example 11: Formula I: R= ethyl: R'= H: n= 1: Rl= C HsOCrSIO (R Configuration). Ascomycin (988.8 mg, 1.25 mmol) was dissolved in 10 mL of methylene chloride in an ice bath. Pyridine (404 uL, 5 mmol) followed by phenoxythiocarbonyl chloride (190 uL, 1.375 mmol) were added. The mixmre was stirred at 0 °C for 5 min and allowed to stir at room temperamre for 24 hours. Additional pyridine (404 uL, 5 mmol) and phenoxythiocarbonyl chloride (190 uL, 1.375 mmol) were added, and stirring was continued for 4 hours. Solvents were evaporated and 40 mL of ethyl acetate was added to the residue. The ethyl acetate layer was washed with 10%-KHSO4 (3 x), brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 1.400 g of cmde product which was purified by silica gel column chromatography, eluting with 5%-ethyl acetate in chloroform. The title compound (730 mg) was obtained. MS (FAB) miz: M+K = 966; IR(KBr) 3420, 2980, 2930, 2870, 2825, 1740, 1705, 1645, 1630, 1590, 1490, 1450, 1375, 1365, 1320, 1280, 1260, 1230, 1200, 1175, 1140, 1100, 1090, 1080, 1035, 1020, 1005 cπr . Example 12: Formula IE: R= ethyl: R'= H: n= 1: R^l= H: R22= H: RSI and R24 taken together form an oxo group: R 3 -^ and R3-6 taken together form an oxo group. To a solution of acetonitrile (5 mL) and 48% hydrofluoric acid (100 uL) was added Example 8b (530 mg, 0.586 mmol) in acetonitrile (7 mL) dropwise, and the mixmre was stirred at room temperamre for 35 in. Ethyl acetate (60 mL) was added to the reaction mixture, and the organic layer was washed with brine, 10%-NaHCθ3, brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 515 mg of crude title compound which was purified by silica gel column chromatography, eluting with 1%-methanol in chloroform. 304.8 mg of pure compound was obtained. MS (FAB) miz: M+K = 828; IR(KBr) 3420, 2960, 2930, 2870, 2820, 1740, 1720, 1645, 1620, 1580, 1450, 1380, 1345, 1325, 1280, 1260, 1245, 1220, 1195, 1170, 1140, 1115, 1100, 1090, 1050, 1035, 1010 cm" 1 . CfiHsOCfS'lO: R3 = H:_R3-£ and R36 taken together form an oxo group. The title compound (460 mg) was isolated from the reaction described in Example 11 as a minor product MS (FAB) miz: M+K = 1103; IR(KBr) 3420, 2980, 2930, 2870, 2820, 1740, 1710, 1645, 1620, 1590, 1490, 1450, 1380, 1365, 1320, 1280, 1260, 1210, 1200, 1140, 1100, 1070, 1035, 1015, 1000 cm" 1 . Examples 14a.and 14b: Formula V: R= ethyl: R'= H: n= 1: R2= H: R2= H: R 3 - and R 4 - taken together form an oxo group: R3-l= H: R32= H: R 3 - - and Retaken together form an oxo group: R3-5. and R-2& taken together form an oxo group. Example 14a: To a solution of oxalyl chloride (240 uL, 2.75 mmol), in methylene chloride (7 mL) was added dimethylsulfoxide (390 uL, 5.5 mmol) over 5 min at -78 °C. The reaction mixture was aged for 30 min at -78 °C. Ascomycin (988.8 mg, 1.25 mmol) in methylene chloride (8 mL) was added dropwise and stirred at -78 °C for 1.5 hours. Triethylamine (1.74 mL, 12.5 mmol) was carefully added and the mixture was stirred at -78 °C for an additional 5 min. It was then allowed to warm to room temperature for 30 min. Ethyl acetate (80 mL) was added to the reaction mixture, and the organic layer was washed with brine, 10%-KHSθ4, brine, 10%-NaHCθ3, brine and dried over anhydrous magnesium sulfate. Evaporation of the solvent yielded 920 mg of crude product This was purified by silica gel column chromatography, eluting with 7%-ethyl acetate in chloroform. 648 mg of pure title compound was obtained. MS (FAB) miz: M+K = 826, M+H = 788, M+H-H 2 0 = 770; IR(KBr) 3420, 2960, 2930, 2870, 2820, 1725, 1645, 1625, 1450, 1380, 1340, 1325, 1280, 1260, 1245, 1220, 1195, 1170, 1130, 1115, 1100, 1090, 1040 cm- 1 . Example 14b: Foimula I: R= ethyl; R r = H; n= 1; R 2 = H; R 2' = H; R 3 and R 4 taken together form an oxo group. (146 mg) was also isolated as a minor product from the above reaction. MS (FAB) miz: M+K = 828, IR(KBr) 3420, 2960, 2930, 2880, 2820, 1725, 1710, 1645, 1450, 1375, 1340, 1325, 1280, 1260, 1245, 1225, 1195, 1170, 1130, 1100, 1090, 1035. This compound was also produced by the procedure described in Example 48. Example 15: Formula VI: R= ethyl: R'= H: n= 1: R21 and R-22 taken together form an oxime. = NR3 -where R2£= hydroxyl: R22= OH: R24= H: R21= H: R32= H: R33-= OH: R3 = H: RSI and R2≤ taken together form an oxime. =NR 3 -&-where R &= hydroxyl. To a solution of ascomycin (4.748 g, 6 mmol) in ethanol (70 mL) were added hydroxylamine hydrochloride (4.172 g, 60 mmol) and pyridine (4.86 mL, 60 mmol). The mixmre was then gently refluxed for 4 hours and kept at room temperature overnight with stirring. After treating the mixmre as described in Example 7, the crude material (4.85 g) obtained was purified by silica gel column chromatography, eluting with 1.5% to 4%-methanol in chloroform. 184 mg of pure title compound was isolated. MS (FAB) miz: M+K = 860, M+H = 822; IR(KBr) 3420, 2960, 2930, 2870, 2820, 1745, 1640, 1450, 1390, 1375, 1350, 1325, 1280, 1265, 1220, 1195, 1170, 1160, 1140, 1100, 1090, 1050, 1040, 1015 cπr 1 . Example 16: Formula I: R= ethyl: R'= H: n= 1: Rl= H. The title compound is prepared according to general literature procedures (Taylor, E. C; Hawks, IE, G. H.; McKillop, A. J. Am. Chem. Soc. 1968, 90, 2421; Corey, E. J.; Sachdev, H. S. J. Am. Chem. Soc. 1973, 95, 8483). To a solution of the product of Example 8b (1 mmol) in dry tetrahydrofuran is added thallous ethoxide (1 mmol) with stirring at 0 °C. The mixmre is stirred at room temperamre for 30 min, and the solvent is removed to a yield powder which is dissolved in benzene, and to which benzylbromide (1 mmol) is added. The mixmre is heated under reflux with stirring for several hours (until the reaction is judged to be complete by TLC analysis), cooled, and filtered. The filtrate is passed through a short column of Florisil to remove traces of thallium (I) bromide, concentrated, and purified on silica gel column chromatography to give the desired compound. Example 17: Formula V: R= ethyl: R'= H; n= 1: R = tert-butyldimethylsilyloxy: R3-l= bromo: R22= bromo: R33- and R3 4 - taken together form an oxo group^R 3 -^ and R3-6 taken together form an oxo group. The title compound is prepared by applying a general method described in the literature (Heffner, R.; Safaryn, J. E.; Joulie, M. M. Tetrahedron Lett. 1987, 28, 6539). A solution of bromine in dioxane is added dropwise to a solution of Example 8b in dioxane under irradiation with a sun lamp (150 watts, 120-125 Volt Duro Lite). After 2 hours of irradiation, ethyl acetate is added to the reaction mixmre. The ethyl acetate layer is washed with brine, dried, evaporated, and purified by silica gel column chromatography to afford pure title compound. Example 18: Formula V: R= ethyl: R'= H: n= 1: Rl= tert-butyldimethylsilyloxy: one of R 3 -^ and R-22 is OH: R-2-3- and R2 4 - taken together form an oxo group:_R2£ and R-3& taken together form an oxo group. The title compound is prepared by applying a general method described in the literature (Anderson, J. C; Smith, S. C. SyN E7T1990, 2, 107). A solution of lithio diisopropylamide in anhydrous tetrahydrofuran (THF) is added dropwise to a solution of Example 8b in THF at -78 °C under nitrogen atmosphere. The mixmre is stirred at -78 °C for 30 min, then oxodiperoxymolybdenum(pyridine)-l,3-dimethyl-3,4,5,6-tetrahydro-2(lH)- pyrirnidinone is added all at once. The mixmre is stirred for an additional 30 min at -78 °C, neutralized with 10% ammonium chloride and extracted with ethyl acetate. The ethyl acetate layer is washed with brine, dried, evaporated, and purified by silica gel column chromatography to afford pure title compound. Example 19: Formula E: R= ethyl: R'= H: n= 1: R^l and R-22- taken together form an oxo group: R22= chloro: R2i= H. To a suspension of thionyl chloride (260 uL, 3.52 mmol) and pyridine (400 uL, 4.9 mmol) in 20 mL of diethyether in an ice bath was added Example 54 (2.0, 1.96 mmol) in 50 mL of diethylether in periods of 10-15 min. It was stirred at 0 °C for 0.5 hours and evaporated to dryness. Ethyl acetate (50 mL) was added to the reaction mixture, and the organic layer was washed with brine (30 mLx3). It was then dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 2.14 g of crude product which was dissolved in 60 mL of acetonitrile and 48%-hydrogen fluoride aqueous solution (300 uL) was added. It was then stirred at room temperature for 0.5 hours. The reaction was partitioned between ethyl acetate (60 mL) and 10%-sodium bicarbonate (20 mL), and the aqueous layer was washed with ethyl acetate (30 mL). The combined organic layers were washed with brine (30 mLx3) and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 1.70 g of crude product which was purified by silica gel (100 g) column chromatography, first eluting with 15%- acetone in hexane, followed by 30%-acetone-hexane.290 mg of pure title compound was isolated. MS (FAB) miz: M+K = 848. mp. 119-120 °C. Example 20: Formula V: R= ethyl: R'= H: n= 1: R 3 - and R - taken together form an oxo group: form an oxo group: RS-i and R 3 -^ taken together form an oxo group. The title compound was prepared by the method described in R. L. Danheiser, R. F. Miller, R. G. Brisbois, S. Z. Park/. Org. Chem 1990, 55, 1959-1964. Accordingly Example 14a (1.0 mmol) in acetonitrile (20 mL) containing water (18 uL), triethylamine (0.21 mL, 1.5 mmol), and methanesulfonyl azide (0.28 mL, 3.0 mmol) was stirred at ambient temperamre for 6 hours, whereupon the volatiles were removed in vacuo. The residue was purified by chromatography on silica gel eluting with a mixture of hexanes and acetone (4:1) which provided the desired product (610 mg) in 75% yield. MS (FAB) miz: M+K-N 2 = 824. IR (CDCl3) 2115 cm- 1 . Example 21: Formula V: R= ethyl: R'= H: n= 1: Rl= tert-butyldimethylsilyloxy: R-21 and R22 taken together form a methylene group: R 3 - 3 - and R^ 4 - taken together form an oxo group^R 3 -^ and R26 taken together form an oxo group. The title compound is prepared by applying a general method described in the literature. To a stirred suspension of zinc in anhydrous tetrahydrofuran (THF) is added methylenediiodide at 25 °C under an argon atmosphere. After 30 min, a THF solution of Ti(OiPr)4 is added. The resulting mixmre is stirred at 25 °C for 30 min. A solution of Example 8b in THF is then added. After being stirred for 3 hours, the mixture is diluted with ethyl acetate, acidified, and extracted with ethyl acetate. The organic extracts are washed with brine, dried, and concentrated. The residue is then purified by silica gel column chromatography to yield pure title compound. Example 22: Formula V: R= ethyl: R'= H: n= 1: Rl= tert-butyldimethylsilyloxy: taken together with one of R 3 -! and R 3 - 2 -. one of R 3 - 3 - and R24 form a bond:_one of R 3 -! and R22-is H: one of R 3 - 3 - and R -is CThC(O)Q: R 3 -^ and R2ό taken together form an oxo group. The title compound is prepared by applying a general method described in the literature (Lakhvich, F. A.; Khlebnicova, T. S.; Akhrem, A. A. Synthesis 1985, 784. Akhrem, A. A.; Lakhvich, F. A.; Budai, S. L; Khlebnicova, T. S.; Petrusevich, 1. 1. Synthesis 1978, 925). The product of Example 8b and a slight excess of acetyl chloride are dissolved in dry methylene chloride and pyridine, and the mixmre is stirred at room temperature for 3-5 hours. The solvent is removed to give a residue that is dissolved in ethyl acetate and then washed with 10%-sodium hydrogen carbonate, 10%-potassium hydrogen sulfate, brine, and dried. The crude product obtained is purified by silica gel column chromatography to yield pure title compound. Example 23: Formula V: R= ethyl: R'= H: n= 1: Rl= tert-butyldimethylsilyloxy: taken together with one of R 3 -^- and R-2 2 -. one of R 3 - 3 - and R2 4 - form a bond: one of R 3 -! and R^is H: one of R-23- and R-^is C HsCTbNH: R-25 and R-2-6 taken together form an oxo group. The title compound is prepared by applying a general method described in the literature (Winkler, J. D.; Hershberger, P. M.; Springer, J. P. Tetrahedron Lett. 1986, 27, 5177). The product of Example 8b and a slight excess of benzylamine are dissolved in benzene and gently refluxed for 3-5 hours. The solvent is removed, and the residue obtained is purified by silica gel column chromatography to yield pure title compound. Example 24: Formula V: R= ethyl: R'= H: n= 1: R- = tert-butyldimethylsilyloxy: taken together with one of R 3 -! and R^ 2 -. one of R 3 - 3 - and R2- 4 - form a bond: one of R 3 -! and R-32-is H: one of Rϋ and RSi-is GJH CH7NH: R 3 -^ and R2& taken together form an oxo group. Benzyl bromide and triethylamine are added to a solution of the product of Example 2 in acetonitrile. The reaction mixture is warmed to 35-45 °C overnight The solvent is removed, and the residue is dissolved in ethyl acetate. The ethyl acetate layer is washed with 10%- sodium hydrogen carbonate, brine, dried over magnesium sulfate, and evaporated. The crude product is purified by silica gel column chromatography. Example 25: Formula I: R= ethyl: R'= H: n= 1: Rl= M CODNH (S Configuration'). The title compound is prepared by applying a general method described in the literature (Neville, R. G.; McGee, J. J. Can. J. Chem. 1963, 41, 2123). A solution of the product of Example 2 in anhydrous benzene is added, dropwise, to a solution of silicon tettaisocyanate in benzene in an ice bath. After the addition is over, the mixture is refluxed for 15 min and concentrated in vacuo. Aqueous isopropyl alcohol (i-propanol : water = 9:1) is added to the residue, and the mixture is refluxed for 15 min. The mixmre is filtered through a coarse-grade sintered-glass funnel and washed with acetone. Solvents are removed, and the residue is dissolved in ethyl acetate. The ethyl acetate layer is washed with 10%-sodium hydrogen carbonate, brine, and dried over magnesium sulfate. After the solvent is removed, the crude product is purified by silica gel column chromatography. Example 26: Formula I: R= ethyl: R'= H: n= 1: Rl= CgHsCHoOCONH (S Configuration). Benzyloxycarbonyl chloride and triethylamine are added to a solution of the product of Example 2 in anhydrous methylene chloride. The reaction mixmre is stirred for 1 hour. The solvent is removed, and the residue is dissolved in ethyl acetate. The ethyl acetate layer is washed with 10%-sodium hydrogen carbonate, brine, dried over magnesium sulfate. After the solvent is removed, the crude product is purified on silica gel column chromatography. Example 27: Formula I: R= ethyl: R'= H: n= 1 : Ri= NHoONHiNH CS Configuration). The title compound is prepared by applying a general method described in the literature (Van Nispen, J. W.; Tesser, G. L; Nivard, R. J. F. Int. J. Peptide Protein Res. 1977, 9, 193). The product of Example 2 is added to a freshly prepared methanolic solution of O- methylisourea. The solution is kept at 0 °C for 1 day, concenttated, and cooled. Water is added slowly to the residue, and the product is extracted with ethyl acetate. The ethyl acetate layer is - 63 - washed with 10%-sodium hydrogen carbonate, brine, dried over magnesium sulfate. After the solvent is removed, the crude product is purified on silica gel column chromatography. The title compound is prepared by applying a general method described in the literature (Kobayashi, T.; lino, K.; Hiraoka, T. J. Am. Chem. Soc. 1977, 99, 5505). Benzenesulfenyl chloride is added dropwise to a solution of Example 2 and triethylamine in methylene chloride at 0 °C. The solution is stirred at 0 °C for 1 hour and at room temperamre for 1 day, concenttated and redissolved in ethyl acetate. The ethyl acetate layer is washed with 10%- sodium hydrogen carbonate, brine, dried over magnesium sulfate. After the solvent is removed, the crude product is purified by silica gel column chromatography. Example 29: Formula I: R= ethyl: R'= H: n= 1: Rl= (CK^C^O)^^). The title compound is prepared by applying a general method described in the literature (Bauer, G.; Hagele, G. Angew. Chem Int. Ed. Engl. 1977, 16, All). The product of Example 9 is dissolved in dry diethylether under nitrogen and treated with triethylphosphite dropwise. After the exothermic reaction has subsided, the reaction mixture is warmed to gentle reflux for 1 hour. The solvent is removed, and the residue is dissolved in ethyl acetate. The ethyl acetate layer is washed with 10%-sodium hydrogen carbonate, brine, dried over magnesium sulfate. After the solvent is removed, the crude product is purified on silica gel column chromatography. Example 30: Formula I: R= ethyl: R'= H: n= 1: Rl= fCgHsObP O. Ascomycin (100 mg, 0.126 mmol) was dissolved in 1 mL of benzene in an ice bath, and triethylamine (35 uL, 0.252 mmol) followed by diphenylchlorophosphate (53 uL, 0.252 mmol) in benzene (1 mL) was added dropwise. After 4-dimethylaminopyridine (DMAP) (10 mg, 0.08 mmol) was added,it was then stirred at room temperature for 2 hours. 10%-Sodium bisulfate was added to the cooled reaction mixmre. After additional benzene (10 mL) was added, die organic layer was washed with 10%-NaHCθ3 (x3), brine (x5) and then dried over anhydrous magnesium sulfate. Evaporation of the solvent gave crude product which was purified by flash silica gel (25 g) column chromatography, eluting 15%-acetone in hexane. 73 mg of pure title compound was isolated. MS (FAB) miz: M+K = 1062. Example 31: Formula I: R= ethyl: R'= H: n= 1: Rl= C HsS. The title compound is prepared by applying a general method described in the literature (Guindon, Y.; Frenette, R.; Fortin, R.; Rokach, J. J. Org. Chem. 1983, 48, 1357). Dried zinc iodide is added to a solution of ascomycin in dry dichloroethane. To the suspension is added thiophenol, and die reaction mixmre is stirred for 1 hour. The reaction is quenched with water, the solvent is removed, and the residue is dissolved in ethyl acetate. The ethyl acetate layer is washed with 10%-sodium hydrogen carbonate, brine, and dried over magnesium sulfate. After the solvent is removed, the crude product is purified on silica gel column chromatography. Example 32: Formula I: R= ethyl: R'= H: n= 1: Rl= CfiHsOfrO. The title compound is prepared by applying a general method described in the literature (Onaka, M.; Kawai, M.; Izumi, Y. Chem. Lett.1983, 1101). Benzyl chloride and powdered zeolite are added to a solution of ascomycin in tetrahydrofuran. The reaction mixture is vigorously stirred under gentle reflux for 5 hours, and then water is added and insoluble material is filtered. The filtrate is evaporated to dryness, and the residue is dissolved in ethyl acetate. The ethyl acetate layer is washed with 10%-sodium hydrogen carbonate, brine, and dried over magnesium sulfate. After the solvent is removed, me crude product is purified on silica gel column chromatography. Example 33: Formula I: R= ethyl: R'= H: n= 1 : Rl= phthalimide (S Configuration). The title compound is prepared by applying a general method described in the literature (Nefkens, G. H. L.; Tesser, G. I.; Nivard, R. J. F. Rec. Trav. Chim. 1960, 79, 688). Example 2 and sodium carbonate are suspended in a mixed solvent of tetrahydrofuran: water (1 : 1) and cooled in an ice batii. Powdered N-carboethoxy phmalimide is added to the reaction mixture which is then stirred at 0 °C for 5 min and at room temperature for 30 min. Insoluble material is filtered, the filtrate is acidified by 10% potassium hydrogen sulfate, and the product is extracted into ethyl acetate. The ethyl acetate layer is washed with 10%-sodium hydrogen carbonate, brine, and dried over magnesium sulfate. After the solvent is removed, the crude product is purified by silica gel column chromatography. Example 34: Formula I: R= ethyl: R'= H: n= 1: Rl= rC H PfO'lNH (S Configuration'). The title compound is prepared by applying a general method described in me literature (Kenner, G. W.; Moore, G. A.; Ramage, R. Tetrahedron Lett. 1976, 3623). The product of Example 2 and diphenylphosphinyl chloride are dissolved in dry tetrahedrofuran and cooled in an ice bath. N-methylmorpholine is added to the reaction mixture which is stirred at 0 °C for 5 min and at room temperature for 5 hours. Insoluble material is filtered, die filtrate is evaporated to dryness, and the product is extracted in ethyl acetate. The ethyl acetate layer is washed with 10%-sodium hydrogen carbonate, brine, and dried over magnesium sulfate. After the solvent is removed, me crude product is purified on silica gel column chromatography. Example 35: Formula I: R= ethyl: R'= H: n= 1: Rl= CCfiHsO' PfO'lNH CS Configuration'). The title compound is prepared by applying a general method described in the literature (Wolfram, M. L.; Conigliaro, P. J.; Soltes, E. J. J. Org. Chem. 1967, 32, 653). The product of Example 2 and diphenylphosphoryl chloride are dissolved in tettahedrofuran and cooled in an ice bath. Triethylamine is added to the reaction mixmre which is stirred at 0 °C for 5 min and at room temperature for 5 hours. Insoluble material is filtered, the filtrate is evaporated to dryness, and the product is extracted in ethyl acetate. The ethyl acetate layer is washed with 10%-sodium hydrogen carbonate, brine, and dried over magnesium sulfate. After the solvent is removed, the crude product is purified on silica gel column chromatography. Example 36.: Formula El: R= ethyl: R'=H: n= 1: R31 and R - 3 - taken together form a bond: R%L= R2 = H: R-3-S and R-36 taken together form an oxo group. The title compound was prepared according to the methods described in the published European Patent Application No. 89192668 of Fisons, P.26, Examplell: mp 124-125 °C, MS (FAB) miz: M+NH4 = 791. Example 37: Formula IE: R= ethyl: R'=H: n= 1: Ra!-:- H: R3 = H: R3^= OH: R-24= H: R25 and R3ά taken together form =N-OCH2C*Hs. A solution of ascomycin (0.791 g), O-benzylhydroxylamine hydrogen chloride (0.320 g) and dimethylaminopyridine (0.26 g) in absolute ethanol (10 mL) was refluxed under nitrogen ovemight After removal of solvent, the solid residue was purified by silica gel chromatography with ether elution. Yield: 0.6 g; mp 92-98 °C; MS (FAB) miz: M+H = 897, M+NH4 = 914. Example 38: Formula VI: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R-26. RZZ. R2S and R-22 form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R 3 -! and R 3 - 3 - taken together form a bond: R3 = H: R24= H: R25 and R36 taken together form an oxo group: R6 Q = OH (7? configuration): R&= H. A solution of the product of Example 36 (0.338 g), o-phenylenediamine (0.05 g) and N- methylmorpholine (0.04 g) in absolute ethanol was refluxed under nitrogen ovemight Solvent was removed in vacuo and the product purified by silica gel chromatography (10 g) with methylene chloride/acetonitrile (5:2, v/v) elution, followed by ether. Yield: 0.3 g; MS (FAB) miz: M+H = 846, M+NH4 = 863. Example 39: Formula E: R= ethyl: R'=H: n= 1 : taken together with the carbon atoms to which they are attached. R-26. R22. R2& and 2S form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R≤fl = OH (R configuration): Rό£= H. A solution of ascomycin (0.41 g), o-phenylenediamine (0.108 g) and N-methylmorpholine (0.072 g) in absolute etiianol (3 mL) was refluxed under nitrogen ovemight Solvent was removed in vacuo and the product purified on silica gel (10 g) with methylene chloride/acetonitrile (5:2, v/v) elution, followed by 40% acetone in hexanes. Yield: 0.396 g; mp 110-120 °C; MS (FAB) miz: M+NH4 = 881. Example 40: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R-26. R-22. R2& and Reform a 6'.7'-dichloroquinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R6 Q = OH (R configuration): R-6≤=- H. The title compound was prepared and purified by the procedure as described in Example 39 substituting 4,5-dicMorophenyl-l,2-diamine for o-phenylenediamine. mp: 107-110 °C; MS (FAB) miz: M+H = 932, M+NH4 = 949. Example 41: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R2&. R22. R2S. and R2£ form a 6'.7'-dimethylquinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R-6 Q = OH (R configuration): R&= H. The title compound was prepared and purified by the procedure as described in Example 39 substi tm 4,5-dimethylphenyl-l,2-diantinefor o-phenylenediamine. mp: 112-115 °C; MS (FAB) miz: M+H = 892, M+NH 4 = 909. Examples 42a and 42b: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R-2 R22. R2& and Reform a 6'-methoxyquinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R6 = OH (R configuration): R65= H. and Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R26. R- 7-. R^ 8 - and Reform a 7'-methoxyquinoxaline with C-9 and C-10 becoming positions and 3' of the heterocyclic system: R-6 = OH (R configuration): R≤5= H. The title compounds were prepared and purified by the procedure described in Example 39 substituting 4-methoxy-phenyl-l,2-diamine for o-phenylenediamine. mp: 117-126 °C; MS (FAB) miz: M+H = 894, M+NH4 = 932. Example 43: Formula E: R= ethyl: R'=H: n= 1 : taken to ether with the carbon atoms to which they are attached. 26. R^X, R^ 8 - and R-22- form a benzorglquinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R£Ω = OH (R configuration): R&= H. The title compound was prepared and purified by the procedure as described in Example 39 substituting 2,3-naphthalenediamine for o-phenylenediamine. mp: 115-120 °C; MS (FAB) miz: M+H = 914, M+NH4 = 931. Example 44: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R26. R22. R-^ 8 - and R-22 form a 6'.7'-methylene-dioxy-quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R6Ω = OH (R configuration): R65= H. The title compound was prepared and purified by the procedure as described in Example 39 substimting 4,5-methylenedioxy-phenyl-l,2-diamine for o-phenylenediamine. mp: 190-193 °C; MS (FAB) miz: M+H = 908, M+NH 4 = 946. Example 45: Formula E: R= ethyl: R'=H: n= 1; taken together with the carbon atoms to which they are attached. R26. R22. R2& and R-22 form a 6'.7'-difluoroquinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R≤ Q = OH (R configuration ' ): R65= H. The title compound was prepared and purified by the procedure as described in Example 39 substimting 4,5-difluorophenyl-l,2-diamine for o-phenylenediamine. mp: 112-116 °C; MS (FAB) miz: M+K = 938. Example 46: Formula II: R= ethyl: R'=H: n= 1 : one of R2Land R22-is H and the other is OH: R22= OH: R2i= H. Zinc dust (5.4 g) was added portionwise into a stirred solution of ascomycin (5.4 g) in glacial acetic acid (50 mL) under nitrogen at room temperature. The reaction mixmre was stirred vigorously at room temperamre for 5 hours until TLC analysis (40% acetone in hexanes) showed the total disappearance of ascomycin. The solid was then filtered off and triturated with methylene chloride. The solvent was removed in vacuo and residue solid was redissolved in methylene chloride, filtered through silica gel eluting witii 50% acetone in hexanes, and concenttated in vacuo. The solid was recrystallized from ether-hexanes. Yield: 4.9 g; mp 138- 140 °C; MS (FAB) miz: M+NH4 = 811. Example 47: Formula El: R= ethyl: R'=H: n= 1: R21=H: R22= H: R22= H: R34= S: R and taken together is N. the S and N is bridged by a phenyl ring to form a benzofhiazepine. A solution of the product of Example 36 (0.26 g) and 2-aminothiophenol (0.05 g) and N- methylmorpholine (0.07 g) in absolute ethanol (3 mL) was refluxed under nitrogen ovemight. Solvent was removed in vacuo, and d e product was purified on silica gel with ether elution. Yield: 0.23 g; mp: 133-138 °C; MS (FAB) miz: M+H = 881. Example 48: Formula I: R= ethyl: R'=H: n= 1: R 2 - = R = H: R - and R - taken together form an oxo group. Methylsulfide-chlorine complex was prepared by adding oxalyl chloride (0.32 g) into a stirred solution of dimethylsulfoxide (0.44 g) in methylene chloride (4 mL) and stirring at -70 °C for 0.5 hours. The solution of the complex was added in slow dropwise fashion into a stirring solution of ascomycin (1.6 g) in methylene chloride (5 mL) at -70 °C. After stirring for 0.25 hours, triethylamine (1.4 g) was added at -70 °C. Stirring was continued at -70 °C for 0.5 hours and then at room temperamre for 1 hour. The reaction mixture was then diluted with ether (100 mL), washed with 1 N HCl (aq) (2x30 mL), saturated brine (30 mL), dried over magnesium sulfate and solvent removed. The product was purified on silica gel (70 g) with ether elution. Yield: 0.95 g; MS (FAB) miz: M+H = 790. Example 49: Formula I: R= ethyl: R=H: n= 1 : R 2 = R21 = H: R- and R - taken together form an 1.3-ethylenethioketal group. Triethyloxonium tettafluoroborate (0.1 mL, 1 M in CH 2 C1 2 ) was added into a stirred solution of ethanedithiol (0.01 mL) and die product of Example 48 (0.05 g) in dry methylene chloride (1 mL) at 0 °C. After stirring at 0 °C and room temperamre for 1 hour, potassium carbonate was added, and the product was purified by prep TLC (40% acetone in hexanes). Yield: 0.02 g; MS (FAB) miz: M+H = 866, M+Na = 888, M+K = 904. Example 50: Formula I: R= ethyl: R'=H: n= 1: R 2 - = R-21 = H: R 3 - and R - taken together form =N-OH. A solution of the product of Example 48 (0.25 g), hydroxylamine hydrochloride (0.03 g) and N-methylmorpholine (0.035 g) in absolute ethanol was refluxed under nitrogen for 1.5 hours. Solvent was removed in vacuo and the product was purified on silica gel with ether elution. Yield: 0.2 g; MS (FAB) miz: M+H = 805. Example 51 : Formula I: R= ethyl: R r =H: n= 1 : R - = R - = R = H: R = OH. Lithium tri-t-butoxyaluminum hydride (0.2 mL, 1 M in THF) was added slowly into a stirred solution of the product of Example 48 (0.056 g) in dry THF (1 mL) at -70 °C under nitrogen. After stirring at -70 °C for 3 hours, it was partitioned between ether (50 mL) and 1 N HCl (10 mL). The organic phase was dried over magnesium sulfate, the solvent was removed and the product purified by prep TLC (35% acetone in hexanes). Yield: 0.025 g; MS (FAB) miz: M+K = 830. Example 52: Formula IE: R= ethyl: R'=H: n= 1 : R3-l= H: taken together with the carbon atoms to which they are attached. R 3 - 3 - R34..R.25 and R-2& form a pyrrazole. Hydrazine (0.014 g, in 2 mL of dry THF) was added into a stirred solution of the product of Example 12 (0.24 g) in dry THF (10 mL) at room temperature. After stirring at room temperature for 0.5 hours, the reaction mixture was refluxed for 2 hours. After removal of the solvent, the product was purified by silica gel chromatography (silica gel, 50 g) eluting with 50% acetone in hexanes. The solid was further purified by prep TLC (5% methanol in methylene chloride). Yield: 0.13 g; MS (FAB) miz: M+H = 786. Example 53: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R2ά. R-22. R2& and R 2 ^ form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system, two of the quinoxalines form a carbon-carbon bond between either the 6' or 7' on each heterocyclic system: RάΩ= OH (R configuration): R65= H. A solution of ascomycin (0.6 g), N-methylmorpholine (0.153 g) and 3,3'-diaminobenzidine tetrahydrochloride (0.1 g) in absolute ethanol was refluxed ovemight The product was purified as described in Example 39. Yield: 0.31 g; mp: 128-132 °C; MS (FAB) miz: M+H = 1725. Example 54: Formula V: R= ethyl: R'=H: n= 1: R-L= t-butyldimethylsilyloxy (R configuration): R31= H: R22= H: R22= t-butyldimethylsilyloxy: R24= H: R-25 and R36 taken together form an oxo group. Ascomycin (15 g) was dissolved in a solution of imidazole (3.75 g) in dry N,N- dimethylformamide (200 mL) and tert-butyldimethylchlorosilane (18.3g) was added in portions and stirred at room temperature for 90 hours. N,N-dimethylformamide and excess tert-butyldimethylchlorosilane were removed by distillation (bath 30 °C at 0.8 torr.). The solid residue was extracted with anhydrous ether (4x50 mL). Etiier was removed in vacuo and die solid residue was purified by silica gel chromatography eluting with 5% acetone in hexanes providing the title compound (17 g). MS (FAB) m/z: M+H = 1022. Example 55: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration-): one of R2Land R2 is H and the other is OH: R22= OH: R24= H: R21= R22= H: R22= t-butyldimethylsilyloxy: R-24= H: R 3 ^ and R2ά taken together form an oxo group. Zinc dust (5 g) was added into a stirred solution of the product of Example 54 (5 g) in glacial acetic acid (25 mL) and stirred at room temperamre for 5 hours. The reaction mixmre was diluted with methylene chloride (150 mL) and the solid was filtered off and extracted with additional methylene chloride (3x50 mL). Solvent was removed in vacuo, and the solid residue filtered through silica gel (20 g) and eluted with ether. Yield: 5 g; MS (FAB) miz: M+H = 1024. Exa ple 56: Formula Vϋ: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration'): one of R2Land R2 is H and the other is OAc: R22= OH: R2i= H: R3J-= R22= H: R-33-= t-butyldimethylsilyloxy: R24= H: R 3 -^ and R3-& taken togedier form an oxo group. Acetic anhydride (1 mL) is added into a stirred solution of die product of Example 55 (1 g) and 4-dimetiιylaminopyridine (0.1 g) in dry pyridine (5 mL). The reaction mixture is stirred at room temperature for 1 hour. Solvent and excess acetic anhydride is removed in vacuo (0.1 torr) and the solid residue is purified by silica gel chromatography eluting with 2% ethanol in methylene chloride. Example 57: Formula V: R= ethyl: R'=H: n= 1: Rl= tri-isopropylsilyloxy (R configuration): group. Triisopropylsilyl trifluoromethanesulfonate (10 g) in dry methylene chloride (25 mL) was added dropwise into a stirred solution of ascomycin (7.8 g) and N-methylmorpholine (4 g) in dry mediylene chloride (100 mL) at 0 °C and stirred at 0 °C for 3 hours. Methanol (3 mL) was added and stirring was continued for an additional hour. Solvent was removed in vacuo and die residue worked up with ether and 1 N hydrochloric acid. The organic phase was dried over magnesium sulfate and solvent removed in vacuo. Purification by silica gel chromatography eluting with 10% ether in hexanes provided the title compund (9 g). MS (FAB) miz: M+Na = 1128. Example 58: Formula VE: R= ethyl: R'=H: n= 1: Rl= tri-isopropylsilyloxy (R configuration): one of R2Land R22 is H and the other is OH: R22= OH: R24= H: R3 = R22= H: R33= tri- isopropylsilyloxy: R34= H: R3-5 and R3- taken together form an oxo group. Zinc dust (5 g) was added into a stirred solution of the product of Example 57 (5 g) in glacial acetic acid (25 mL) and stirred at room temperature for 5 hours. The reaction mixture was diluted witii methylene chloride (150 mL) and the solid was filtered off and extracted with methylene chloride (3x50 mL). The resulting solution was filtered through silica gel (20 g) and eluted with ether. Yield: 5 g; MS (FAB) miz: M+Na = 1130. Example 59: Formula VE: R= ethyl: R'=H: n= 1: Rl= tri-isopropylsilyloxy (R configuration): one of R2Land R22 is H and the other is OAc: R22= QH: R2i= H: R21= R22= H: R22= tri- isopropylsilyloxy: R34= H: R3-£ and R 3 -^ taken together form an oxo group. Acetic anhydride (1 mL) was added into a stirred solution of the product of Example 58 (1 g) and 4-dimemylaminopyridine (0.1 g) in dry pyridine (5 mL). The reaction mixture was stirred at room temperature for 1 hour. Solvent and excess acetic anhydride was removed in vacuo (0.1 torr) and the sohd residue was purified by silica gel chromatography eluting with 2% ethanol in methylene chloride. Yield: 1 g; MS (FAB) miz: M+Na = 1172. Example 60: Formula E: R= ethyl: R'=H: n= 1 : one of R2L-and R^ 2 - is H and the other is OAc: R22= OH: R24= H. 40% Aqueous hydrofluoric acid (0.5 mL, in 5 mL of acetonitrile) is added dropwise into a solution of the product of Example 59 (1.1 g) in acetonitrile (10 mL) at 0 °C. The reaction mixture is stirred at room temperamre for 2 hours. The reaction mixture is diluted with water (50 mL) and extracted with ethyl acetate (3x50 mL), dried over magnesium sulfate and die solvent removed in vacuo. The crude is purified by silica gel chromatography using 5% methanol in methylene chloride as eluent Example 61: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which thev are attached. R2ό. R2Z R2S and R2£ form a 2'-methyl-thiazole with C-9 and C-10 becoming positions 5' and 4' of the heterocyclic system: R6Ω= OH (R configuration ' ): &= H. A solution of the product of Example 60 (0.83 g), thioacetamide (0.15 g) and triethylamine (0.2 g) in isopropanol (5 mL) is refluxed under nitrogen for 16 hours. Solvent is removed in vacuo and die solid residue is purified by silica gel chromatography eluting first with 20% acetonitrile in methylene chloride followed by 7% methanol in methylene chloride. Example 62: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R2ό. R-2-7. R-2& and R-22 form a 2'-amino-thiazole with C-9 and C-10 becoming positions 5' and 4' of the heterocyclic system: R6Ω= OH (R configuration): R65= H. A solution of the product of Example 60 (0.1 g), thiourea (0.015 g) and triethylamine (0.2 g) in acetonitrile (1 mL) is refluxed under nitrogen for 16 hours. Solvent is removed in vacuo and the solid residue is purified by silica gel chromatography eluting first with 20% acetonitrile in methylene chloride followed by 7% methanol in methylene chloride. Example 63: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which thev are attached. R26. R2Z. R2& and R2£ form a 2'-phenyl-imidazole with C-9 and C-10 becoming positions 5' and 4' of the heterocyclic system: R = OH (R configuration'): R≤5= H. A solution of the product of Example 60 (0.83 g), benzamidine hydrochloride hydrate (0.3 g) and triethylamine (0.2 g) in isopropyl alcohol (5 mL) is refluxed under nitrogen for 24 hours. Solvent is removed in vacuo, and die solid residue is purified by silica gel chromatography eluting with 10% medianol in methylene chloride. Example 64: Formula E: R= ethyl: R'=H: n= 1 : taken together with the carbon atoms to which they are attached. R26. R2Z R2 and R2£ form a 2'-phenyl-oxazole with C-9 and C-10 becoming positions 5' and 4' of the heterocyclic system: R≤ Q = OH (R configuration): R-65= H. A solution of the product of Example 60 (0.83 g), benzamide (0.25 g) and trietiiylamine (0.2 g) in acetonitrile (5 mL) is refluxed under nitrogen for 24 hours. Solvent is removed in vacuo and me solid residue is purified by silica gel chromatography eluting with 10% methanol in methylene chloride. Example 65: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration'): one of R2Land R22 js ri-r2'2'.5'.5'-tetramethyl-2'5'-disila-l'-azolidinyl)l-2- ethyl and the other is OH: R2≥= OH: R2 = H: R-3-l= R22= H: R = t-butyldimethylsilyloxy: R34= H: R-2S and R taken togedier form an oxo group. To a solution of the product of Example 54 (1 g) in dry tetrahydrofuran (10 mL) is added with stirring at 0 °C l-(2-ethyl)-2,2,5,5-tetramethyl-2,5-disila-l-azacyclopentane magnesium bromide (1 M in THF, 1.5 mL). The reaction mixture is allowed to reach room temperamre and stir for 4 hours. The reaction mixture is worked up with saturated ammonium chloride (50 mL) and extracted with ethyl acetate (3 x 50 mL). The combined organic phase is washed with water, brine and dried over magnesium sulfate. The product is purified by silica gel chromatography eluting with 3% methanol in methylene chloride. Example 66: Formula E: R= ethyl: R'=H: n= 1 : taken together with the carbon atoms to which they are attached. R26. R22. R2& and R2S form a pyrrole with C-9 and C-10 becoming positions and 2' of the heterocyclic system: R6Ω= OH (R configuration'): Rά5= H. 40% Aqueous hydrofluoric acid (1 mL) is added dropwise into a solution of the product of Example 65 (1.1 g) in acetonitrile (10 mL) at 0 °C. The reaction mixture is stirred at room temperature for 2 hours. The reaction mixmre is diluted witii water (50 mL), extracted with ethyl acetate (3x50 mL), dried over magnesium sulfate and the solvent is removed in vacuo. The crude is purified by silica gel chromatography using 5% methanol in memylene chloride as eluent Example 67: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration): taken togedier with the carbon atoms to which they are attached. R-2S. R-2I. R2& and Reform a pyrazine with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R32= t-butyldimethylsilyloxy: R3-l= H: R32= H: R34= H: R25 and R-36 taken together Activated manganese dioxide (1.1 g) is added into a solution of the product of Example 54 (1.1 g) and ethylenediamine (0.1 g) in dry benzene, and the suspension is stirred at 50 °C for 24 hours. The solid is filtered off, and solvent is removed in vacuo. The product is purified by silica gel chromatography eluting with 3% methanol in methylene chloride. Example 68: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R26. R2 . R^ 8 - and R22 form a pyrazine with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R6Ω= OH (R configuration): R&= H. The product of Example 67 is deprotected to give die tide compound and purified according to the procedure of Example 60. Example 69: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration'): one of R21 and R22- is r2-(1.3-dioxolanyl)]-2-efhyl and the other is OH: R23-= OH: R24= H: R21= R22= H: R21= t-butyldimethylsilyloxy: R24= H: R-35 and R2ό taken together form an oxo group. To a solution of the product of Example 54 (1 g) in dry tetrahydrofuran (10 mL) is added under stirring at 0 °C 2-(2-ethyl)-l,3-dioxolane magnesium bromide (1 M in THF, 1.5 mL). The reaction mixmre is allowed to reach room temperature and stir for 4 hours. The reaction mixture is worked up with saturated ammonium chloride (50 mL) and extracted with ethyl acetate (3x50 mL). The combined organic phases are washed with water, brine and dried over magnesium sulfate. The product is purified by silica gel chromatography eluting with 3% methanol in methylene chloride. Example 70: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration): taken together with the carbon atoms to which they are attached. R^6. R22. R2& and R-22 form a pyridine with C-9 and C-10 becoming positions 3' and 2' of the heterocyclic system: R22= t-butyldimethylsilyloxy: R3-l= H: R22= H: R2 = H: R 3 ^ and R-2-6 taken together form an oxo group: R-6Ω= OH (R configuration): R &= H. A solution of the product of Example 69 (1 g), oxalic acid (0.2 g) and acetaldehyde (0.5 mL) in wet metiiylene chloride (5 mL) is stirred under nitrogen overnight Solvent is removed in vacuo and the reaction crude is partitioned between ethyl acetate and aqueous sodium bicarbonate. The solution is dried over magnesium sulfate and the solvent is removed in vacuo. The residue is redissolved in isopropyl alcohol (5 mL) and ammonium hydroxide (0.5 mL) is added. The reaction mixture is allowed to stir at room temperature ovemight. After removal of solvent in vacuo, the product is purified by silica gel chromatography eluting with 40% acetone in hexanes. Example 71 : Formula E: R= ethyl: R'=H: n= 1 : taken together with the carbon atoms to which they are attached. R2ά. R22. R-2& and 2 ^ form a pyridine with C-9 and C-10 becoming positions 3' and 2' of the heterocyclic system: R6Ω= QH (R configurationV. Rά5= H. The product of Example 70 is deprotected and purified according to me procedure of Example 60 to give the title compound. Example 72: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R 2 ^. R22. R2& and R^ form a pyridazine with C-9 and C-10 becoming positions 4' and 3' of the heterocyclic system: R6Ω= OH (R configuration ' ): Rfi5= H. A solution of the product of Example 69 (1 g), oxalic acid (0.2 g) and acetaldehyde (0.5 mL) in wet methylene chloride is stirred under nitrogen ovemight Solvent is removed and die reaction mixture is partitioned between ethyl acetate and aqueous sodium bicarbonate. After removal of the solvent the residue is redissolved in isopropyl alcohol (5 mL) and hydrazine (0.035 g) is added. The reaction mixmre is allowed to stir at room temperature overnight. After removal of solvent, the bis-silylated product is purified by silica gel chromatography and is deprotected according to the procedure of Example 60. Example 73: Formula E: R= ethyl: R'=H: n= 1: taken togedier with the carbon atoms to which they are attached. R^6. R22. R-2& and R 2 ^ form a pyrazinor2.3-d]pyridazine with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R^Ω= QH (R configuration): R&= H. A solution of ascomycin (0.8 g), 4,5-diaminopyridazine (0.2 g) and N-methylmorpholine (0.2 g) in isopropyl alcohol (5 mL) is heated at 80 to 90 °C for 12 hours. Solvent is removed and product purified by silica gel chromatography eluting with 40% acetone in hexanes. Examples 74a and 74b: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R26. R2I. R2& and R22 form a pyridor3.4-b1pyrazine with C- 9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R6Ω= OH (R configuration): Rfi5= H. and Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R 6 R-2Z. R^ 8 - and R 2 form a pyridor3.4-fr]pyrazine with C-9 and C-10 becoming positions 3' and 2' of the heterocyclic system: R≤Ω= OH R configuration): R65=H. A solution of ascomycin (0.8 g), 4,5-diaminopyridine (0.2 g) and N-methylmorphohne (0.2 g) in isopropyl alcohol (5 mL) is heated at 80 to 90 °C for 12 hours. Solvent is removed, and the products purified by sihca gel chromatography eluting witii 40% acetone in hexanes. Examples 75a and 75b: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R2&. R22. R-2& and R-2J form a pyridor2.3-blpyrazine with C- 9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R≤ Q = OH.(R configuration): Rό5= H. and Formula II: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R-26, R-22. R-2& and R22- form a pyridor2.3-b1pyrazine with C-9 and C-10 becoming positions 3' and 2' of the heterocyclic system: R23-= OH: R&= H: R6Ω= OH (R configurationl: R = H. A solution of ascomycin (0.8 g), 2,3-diaminopyridine (0.2 g) and N-methylmorpholine (0.2 g) in isopropyl alcohol (5 mL) is heated at 80 to 90 °C for 12 hours. Solvent is removed, and the products are purified by silica gel chromatography eluting with 40% acetone in hexanes. Examples 76a and 76b: Formula II: R= ethyl: R'=H: n= 1 : taken together with the carbon atoms to which they are attached. R-2A R22. R2£ and R 2 ^ form a pteridine with C-9 and C-10 becoming positions 7' and 6' of the heterocyclic system: R6Ω= QH (R configuration ' ): R-&= H and Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R26. R22, R2& and R22 form a pteridine with C-9 and C-10 becoming positions 6' and 7' of the heterocyclic system: R≤Ω= OH (R configuration): R-65= H. A solution of ascomycin (0.8 g), 4,5-diaminopyrimidine (0.2 g) and N-methylmorpholine (0.2 g) in isopropyl alcohol (5 mL) is heated at 80 to 90 °C for 12 hours. Solvent is removed and products purified by silica gel chromatography eluting with 20% methanol in methylene chloride. Example 77: Formula V: R= ethyl: R'=H: n= 1: Rl= H: R-31= R22= H: R-22= t- butyldimethylsilyloxy: R-24= H: R 3 -^ and R-26 taken together form an oxo group. To a solution of me product of Example 259 (15 g) and imidazole (3.75 g) in dry N,N- dimethylformamide (200 mL), tert-butyldimediylchlorosilane is added in portions and stirred at room temperamre for 90 hours. N,N-dimethylformamide and excess tert- butyldimethylchlorosilane is removed by distillation (batii 30 °C at 0.8 torr.). The solid residue is extracted with anhydrous ether (4 x 50 mL). Ether is removed in vacuo and the solid residue is purified by silica gel chromatography eluting witii 5% acetone in hexanes. Example 78: Formula VE: R= ethyl: R'=H: n= 1: Rl= H: one of R21 and R22-is n-butyl and the other is OH: R22= OH: R24= H: R&= R32= H: R33-= t-butyldimethylsilyloxy: R24= H: R25 and RS * taken together form an oxo group. The product of Example 77 (0.5 g) is dissolved in dry tetrahydrofuran (10 mL) and cooled to -78 °C. n-Butyl lithium (1.6 M in Hexanes, 0.5 mL) is added in slow dropwise. The reaction mixture is allowed to stir at -78 °C for 2 hours and worked up with saturated ammonium chloride and etiier. Product is purified by silica gel chromatography eluting w h ether. Example 79: Formula IV: R= ethyl: R'=H: n= 1 : Rl= H: one of R 2 ! and R22-is n-butyl and the other is OH: R 2 - = OH: R ! = OH: R-2ά= H. The product of Example 78 is deprotected and purified according to the procedure of Example 60 to give the title compound. Example 80: Formula VE: R= ethyl: R'=H: n= 1: Rl= H: one of R2 and R22-is benzyl and the other is OH: R23= OH: R2 = H: R3 = R22= H: R32= t-butyldimethylsilyloxy: R34= H: R- and R taken together form an oxo group. The product of Example 77 (0.5 g) is dissolved in dry tetrahydrofuran (10 mL) and cooled to - 78 °C. Benzylmagnesϊum chloride (2 M in tetrahydrofuran, 0.5 mL) is slowly added dropwise. The reaction mixture is allowed to stir at -78 °C for 1 hour, 0 °C for 4 hours and worked up with saturated ammonium chloride and etiier. The product is purified by silica gel chromatography eluting witii ether. Example 81 : Formula IV: R= ethyl: R'=H: n= 1 : Rl= H: one of R21 and R-Zljs benzyl and the other is OH: R23= OH: R24= H. The product of Example 80 is deprotected and purified according to die procedure of Example 60 to give the tide compound. Example 82: Formula VE: R= ethyl: R'=H: n= 1: Rl= H: one of R2I and R22-is hydrogen and the other is OH: R23-= OH: R24= H: R31= R22= H: R33= t-butyldimethylsilyloxy: R = H: R25 and R2-i taken together form an oxo group. The product of Example 82 is prepared from the product of Example 77 and purified according to procedure of Example 58. Example 83: Formula VE: R= ethyl: R'=H: n= 1: Rl= H: one of R21 and R22-is hydrogen and the other is O. which when taken together with R22= O. botii oxygens are connected witii a thiocarbonyl bridge: R24= H: R21= R22= H: R2S= t-butyldimethylsilyloxy: R34= H: R25 and R taken together form an oxo group. O-Phenyl chlorothioformate (0.07 g) is added into a stirred mixture of the product of Example 82 (0.3 g) and 4-dimemylaminopyridine (0.3 g) in anhydrous acetonitrile (5 mL). After stirring at room temperature for 1 hour, the solution is diluted witii etiier (30 mL) and washed with brine. The organic phase is dried over magnesium sulfate, and die solvent is removed in vacuo. The residue is purified by silica gel chromatography eluting with 20% acetone in hexanes. Example 84: Formula IV: R= ethyl: R'=H: n= 1: Rl= H: one of R21 and R22-is hydrogen and the other is O. which when taken together with R22= O. both oxygens are connected with a thiocarbonyl bridge: R 2 ^ H. The product of Example 83 is deprotected and purified according to the procedure of Example 60 to give the title compound. Example 85: Formula VE: R= ethyl: R'=H: n= 1 : Rl= H: one of R21 and R22-is hydrogen and the other is O. which when taken together with R22= O. both oxygens are connected with a carbonyl bridge: R24= H: R3JL= R-22= H: R23-= t-butyldimethylsilyloxy: R3i= H: R-25 and R-26 taken together form an oxo group. The product of Example 82 (1 g) is dissolved in 1,2-dichloroethane (15 mL) and N,N- carbonyldiimidazole (0.188 g) is added in portions to me mixture with stirring. After stirring at room temperature for 26 hours, the solvent is removed in vacuo and the residue is purified by silica gel chromatography eluting witii 10 % acetone in hexanes. Example 86: Formula IV: R= ethyl: R'=H: n= 1: R-l= H: one of R21 and R-22-is hydrogen and the other is O. which when taken together with R23-= O. both oxygens are connected with a carbonyl bridge: R-24= H. The tide compound is prepared from the product of Example 85 and purified according to the procedure of Example 60. Example 87: Formula VE: R= ethyl: R'=H: n= 1: Rl= H: one of R 1 and R2 -is hydrogen and the otiier is O. which when taken together with R23-= O. both oxygens are connected with a PfOVOCTh): R24= H: Rϋ= R32= H: R22= t-butyldimethylsilyloxy: R34= H: R and R taken together form an oxo group. Methyl dichlorophosphate (0.15 g) in methylene chloride (10 mL) is added into a stirred mixmre of the product of Example 82 (1 g) and 4-dimetiιylaminopyridine (0.5 g) in anhydrous methylene chloride (15 mL). After stirring at room temperature for 27 hours, solvent is removed in vacuo. The residue is diluted with ethyl etiier (100 mL) and washed with brine, dried over magnesium sulfate and the solvent is removed in vacuo. The residue is purified by silica gel chromatography eluting with 20% acetone in hexanes. Example 88: Formula IV: R= ethyl: R'=H: n= 1: Rl= H: one of R21 and R22-is hydrogen and the other is O. which when taken together with R22= O. both oxygens are connected with a PfOVOCH^: R2i= H. The title compound is prepared from the product of Example 87 according to die procedure of Example 60. Example 89: Formula IV: R= ethyl: R'=H: n= 1 : Rl= H: one of R 1 and R22-is n-butyl and the other is O. which when taken together with R23-= O. both oxygens are connected witii a thiocarbonyl bridge: R 24 ^ H. The tide compound is prepared from the product of Example 78 by using the procedures described in Example 84. Example 90: Formula IV: R= ethyl: R'=H: n= 1 : Rl= H: R21 is n-butyl: R2 and R23- taken togedier form a bond: R 2 ^ H. To a mixture of the product of Example 89 (0.5 g) and 2,2'-azobisisobutyronitrile (catalytic amount) in anhydrous toluene (10 mL) is added tri-n-butyltin hydride (1 mL) over 0.5 hours. The solvent is removed in vacuo and die residue is purified by silica gel chromatography eluting with 10 % acetone in hexanes. Example 91 : Formula IV: R= ethyl: R'=H: n= 1 : Rl= H: R21= H: R22 and R23- taken together form abond: R2 4 =H. The tide compound is prepared from the product of Example 84 using the procedure described in Example 90. Example 92: Formula IV: R= ethyl: R =H: n= 1 : Rl= H: R21= R22= H: R22= OH: R2 = H. Zinc dust (1 g) is added into a stirred solution of the product of Example 86 (0.5 g) in glacial acetic acid (5 mL) and stirred at room temperature for 35 hours. The reaction mixmre is diluted witii methylene chloride (150 mL) and die solid is filtered off and triturated with mediylene chloride (3x50 mL). Solvent is removed in vacuo, and die residue is purified with silica gel chromatography (10 g) eluting with ether. Example 93: Formula IV: R= ethyl: R'=H: n= 1: Rl= H: one of R21 and R-^ js n-butyl and die other is O. taken togedier with R23-= Q. both oxygens are connected with a carbonyl bridge: R2 4 = H. The tide compound is prepared from the product of Example 78 according to the procedures used in Example 86. Example 94: Formula IV: R= ethyl: R'=H: n= 1: R-l= H: one of R21 and R22-is n-butyl and the other is H: R23= OH: R24= H. The title compound is prepared from the product of Example 93 according to die procedures used in Example 92. Examples 96a and 96b: Formula El: R = ethyl: R' = H: n = 1 : R-21 = R =. H: taken together with the carbon atoms to which they are attached. R 3 - 2 - and R 3 - 3 - form a 3-phenyl-2-isoxazoline with C-23 and C-24 becoming positions 4' and 5' respectively of the heterocyclic system: R 3 -^ and R taken together form an oxo group: and Formula IE: R = ethyl: R' = H: n = 1: R-21 = R34 = H: taken together with the carbon atoms to which they are attached. R22 and R-23- form a 3-phenyl-2-isoxazoline with C-23 and C-24 becoming positions 5' and 4' respectively of the heterocyclic system: R 3 ^ and R36 taken together form an oxo group. N-Chlorosuccinimide (2.67 g, 20 mmol) was suspended in chloroform (20 mL) with pyridine (0.1 mL). Benzaldehyde oxime (2.42 g, 20 mmol) was added to the suspension. Twenty minutes hence, the N-chlorosuccinimide had dissolved, and the resultant solution was stored under nitrogen. The product of Example 36 (1.006 g, 1.29 mmol) was dissolved in dry chloroform. The hydroxamic acid chloride solution (4 mL) prepared above was introduced, and the mixture was heated to 48°C as triethylamine (0.4 mL) was slowly added. After 25 hours, the reaction mixmre was cooled, and the volatiles were removed under reduced pressure. The crade material was purified by flash chromatography over sdica gel (elution with hexanes:acetone 3:2) to supply the tide compounds . Example 96a: IR (CDCI3) cnr* 3420, 2950, 1780, 1750, 1720, 1340, 1160; *H ΝMR . (CDCI3, 500 MHz) delta 7.70-7.35 (m, 5 H), 5.38 (s, 1 H) & 5.15 (d, J = 7.7 Hz, 1 H), 4.73 (dd, J = 6, 10 Hz, 1 H) & 4.64 (coupling obscured), 4.16 (d, J = 7 Hz, 1 H) & 4.13 (d, J = 7 Hz, 1 H); MS (FAB) iz: M + K = 931. Example 96b: IR (CDCI 3 ) cm" 1 2930, 1750, 1720, 1700, 1650, 1450, 1090; *H ΝMR (CDCI3, 500 MHz) delta 5.37 (d, J = 1 Hz, 1 H) & 5.23 (d, J = 3 Hz, 1 H), 5.18 (br s, 1 H) & 4.89 (d, J = 7.7 Hz, 1 H), 4.30 (m, 1 H) & 4.05 (m, 1 H); MS (FAB) miz: M + K = 931. Examples 97a and 97c: Formula IE: R = ethyl: R' = H: n = 1: R J = H: R22 = -CfO Ph: R23. = hydroxy: R-24 = H: R 3 -^ and R-3-ό taken togedier form an oxo group: and Formula El: R = ethyl: R' = H: n = 1: R21 and R23- taken together form a bond: R3 = -CfO'lPh: R = H: R-25 and Re¬ taken together form an oxo group. Example 97a: The product of Example 96a (51.7 mg,.058 mmol) is dissolved in acetonitrile containing 1% water (5 mL) to which molybdenum hexacarbonyl (7.6 mg, 0.029 mmol) is added. The mixmre is heated to reflux for several hours turning a darker blue throughout this time. The reaction mixture is cooled, and a small amount of silica gel is added prior to solvent removal under reduced pressure. The residue is applied to a silica gel column and the title product, die beta-hydroxy ketone, as well as the dehydration product Example 97c, are eluted with ether. Example 97b: Formula IE: R = ethyl: R' = H: n = 1: R-^l = H: R& = hvdroxy: R- 3 - = -CCO^Ph: R-2 4 - = H: R2£ and R3≤ taken together form an oxo group. The product of Example 96b is reduced in the presence of water using the methodology described above to furnish the tide compound. Example 102: Formula IE: R= ethyl: n=l: R r = H: R21= H: R22= H: R22= OH: R^= H: R- and R3≤ taken together is =NR3&: R-2&= -OCTbCOOH. Ascomycin (300 mg, 0.4 mmol), carboxymethoxylamine hemi-hydrochloride (250 mg,1.2 mmol) and pyridine (100 uL,1.2 mmol) in etiianol 10 mL were refluxed for 4 hours. The solvent was evaporated, and the residue was taken up in EtOAc, washed sequentially witii H 2 0, dilute acid (0.2 M H3PO4), and brine and dried over Na 2 S04. Concentration under vacuum gave 430 mg of crade material which was purified by reverse phase-HPLC (21.4 mm ID x 25 cm, C18, 8 μm silica, DYNAMAX preparative HPLC (Rainin)). Elution (15 mL/min) was performed with a linear gradient from 55:45 (H 0-CH3CN containing 0.1% TFA) to 10:90 over 30 min. Combination of selected fractions, evaporation of CH3CN and lyophilization gave 124 mg of the tide compound. MS (FAB) miz: M+K = 903. Example 103a: Formula El: R= ethyl: n=l: R'= H: R21= H: R22= H: R22= OH: R34= H: R3 = QH fS-configuration): R3≤= H: To a solution of 48% aqueous HF (16 uL) in CH3CN (1 mL) was added die product of Example 103c. below (S-isomer, 70 mg) in CH3CN (1 mL). The mixmre was stirred for 0.5 hours. The solvent was removed, and die crude material was purified by silica gel column chromatography using 2% MeOH/CH 2 Cl , yielding 48 mg of the title compound. MS (FAB) miz: M+K 814. Example 103b: Formula IE: R= ethyl: n=l: R'= H: R3L= H: R22= H: R22= OH: R3i= H: R3-5= H: R36= OH fR-configuration). The title compound was prepared using a procedure analogous to that of Example 103a, starting from the product of Example 103d, below. Examples 103c and 103d: Formula V: R= ethyl: n=l : R'= H: Rl= t-butyldimethylsilyloxy: R3J H; R22= H: R32= OH: R = H: R&= OH fS-configuration'): R&= H: and Formula V: R= ethyl: n=l: R'= H: Rl= t-butyldimethylsilyloxy: R3 = H: R22= H: 22= OH: R = H: R35= H: R3ά= OH fR-configuration). To a solution of the product of Example 8a (100 mg, 0.1 mmol) and sodium triacetoxyborohydride (25.7 mg, 0.11 mmol) in CH3CN (1 mL) at 0 °C was slowly added acetic acid (24 uL, 0.33 mmol). After stirring at 0 °C for 2 hours, the reaction mixture was quenched with water and stirred for an additional 0.5 hours. The solution was extracted witii EtOAc, the organic phase was washed witii H 0, brine and dried over Na 2 Sθ 4 . Evaporation of the solvent gave 94 mg of the crade material which was chromatographed over silica gel using 20% EtOAc/CHCl3 as an eluent Unreacted starting material (10 mg), 18 mg of Example 103d, the silylated minor isomer (R), and 52 mg of Example 103c, the silylated major isomer (S), were collected. Example 104a: Formula V: R= ethyl: n=l: R'= H: Rl= t-butyldimethylsilyloxy: R3-l= H: R22= H: R22= QH: R24= H: R25= OSi(Me2Vt-Bu fS-configuration'): R26= H. To a solution of the product of Example 103c, below (1.0 g, 1.1 mmol) in CH 2 C1 (20 mL) was added t-butyldimethylsilyl chloride (730 mg, 4.84 mmol) and imidazole (660 mg, 9.68 mmol). This was stirred at room temperature for 5.5 hours. The reaction mixture was quenched with saturated NH4CI, and diluted witii EtOAc. The organic phase was washed with saturated NH 4 CI, saturated NaHCθ 3 , brine and dried over Na Sθ 4 . The solvent was evaporated and 1.32 g of the crade material was chromatographed over silica gel column to give 868 mg of disilylated product and 140 mg of the recovered starting material. Example 104b: Formula V: R= ethyl: n=l: R'= H: Rl= OSi(Me2)-t-Bu: R3-l= H: R2 = H: RSI and R24 taken together form an oxo group: R25= t-butyldimethylsilyloxy (S-configuration): R3S= H. To a -78 °C solution of oxalyl chloride (40 uL, 0.44 mmol) in 1 mL of methylene chloride was added a solution of dimethylsulf oxide (60 ul, 0.88 mmol) in 1 mL of methylene chloride and the mixmre was aged at -78 °C for 30 min, A solution of the disilylated product of Example 104a (170 mg, 0.2 mmol) in methylene chloride (1 mL) was added. The reaction was carried out at -78 °C for 3 hours with stirring and triethylamine (270 uL, 2.0 mmol) was added. After stirring at -78 °C for 20 min, it was then allowed to stand to room temperature for 30 min. The reaction mixture was partitioned between 40 mL of ethylacetate and 10 mL of 10%-NaHSθ4 solution. The organic layer was washed with 10%-NaHSθ 4 , water (x 3), brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 160 mg of the crade material. Example 104c: Formula El: R= ethyl: n=l : R'= H: R-21= H: R22= H: a! and R-34 taken togedier form an oxo group: R3-5= OH fS-configuration): R2ά= H. Aqueous HF cleavage of the resultant product of Example 104b followed by silica gel column purification provided 85 mg of die title compound. MS (FAB) miz: M+K = 830. Example 105a: Formula E: R= allyl: R'=H: n= 1 : taken together with the carbon atoms to which they are attached. R3&. R 2 ^. R^ 8 - and R22 form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R6& = OH (R configuration): R^= H. A solution of FK-506 (0.41 g), o-phenylenediamine (0.108 g) and N-metiiylmorpholine (0.072 g) in absolute ethanol (3 mL) is refluxed under nitrogen overnight Solvent is removed in vacuo and product is purified on silica gel (10 g) wit methylene chloride/acetonitrile (5:2, v/v) elution, fallowed by 40% acetone in hexanes to give the desired compound. Example 105b: Formula E: R= propyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R-2&. R22, R2& and R-2J form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R& = OH (R configuration): R^= H. The product of Example 105a (150 mg) and 10% Pd/C (30 mg) in ethylacetate (6 ml) are hydrogenated at room temperature for 20 min at 1 atm. The catalyst is filtered, the solvent is concenttated, and the resulting crade material is purified by silica gel column chromatography (eluting solvent chloroform/acetone 5:1) to give the title compound. and Formula V: R= ethyl: R'=H: n=l: Rl= OCOCHoO HN-FMOC: R-3i= H: R32= H: R&= OCOCHoCJF HN-FMOC: R3 =H: RSI and R-26 taken together form an oxo group. To a stirred solution of ascomycin (142.5 mg, 0.180 mmol) and FMOC-beta-alanine (56.0 mg, 0.180 mmol) in dry dichlorometiiane (1.8 mL) were added l-(3-dimethylamino propyl)-3- ethylcarbodiimide hydrochloride (38.0 mg, 0.198 mmol) and DMAP (2.2 mg, 0.018 mmol). After 2.5 days, more FMOC-beta-alanine (42.0 mg) and DMAP (1.5 mg) were added. After 6 hours, the mixture was evaporated, and the residue was chromatographed on silica gel using ether/dichloromethane (1/2) as eluent Combination of selected fractions provided die less polar bis-acylated product Example 106b lH NMR (500 MHz, CDCI3) delta 2.55 (br, 4H), 3.32 (s, 3H), 4.37(br d, 2H),4.42 (br d, 2H), 7.32 (t, 4H), 7.39 (t, 4H), 7.59 (d, 2H), 7.61 (m, 2H), 7.76 (d, 4H).) as well as the mono-acylated product Example 106a (76 mg): X H NMR (500 MHz, CDCI3) delta 2.55 (br), 3.32 (s, 3H), 4.42 (br d), 5.49 (m, IH), 7.32 (t, 2H), 7.39 (t, 2H), 7.59 (d, 2H), 7.76 (d, 2H). Example 107: Formula I: R= ethyl: R'=H: n=l: Rl= OCOCH^CH NHo To a stirred solution of the product of Example 106a (9.0 mg, 0.0082 mmol) in dry THF (0.8 mL) was added piperidine (4.0 uL, 0.041 mmol). After TLC showed complete reaction, the solvent was evaporated, and the solid residue was triturated 3 times with ether/hexane (1/2) to give the desired product as a white solid. Yield: 5.5 mg. MS (FAB) miz: M+K = 901. Example 108: Formula IV: R= propyl: R'=H: n= 1: Rl= benzoyloxy taken together with the carbon atoms to which they are attached. R26. R27. R28 and R29 form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of die heterocyclic system: R6Ω= QH (R configuration'): Rά5= H. To a stirred 0 °C solution of d e resultant compound of Example 105b (32 mg) in dry THF (200 uL) are added benzoyl chloride (20 uL) and pyridine (50 uL). After TLC shows consumption of the resultant compound of example 105b, the solvent is evaporated, and d e residue is chromatographed on silica gel. Combination of selected fractions provides die mono-acylated product Example 108. Example 109: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH^CfO'lOCoHs (R configuration'). A solution of ascomycin (0.5 g, 0.63 mmol) in dichloromethane (10 mL) containing rhodium(E)acetate dimer (3 mg) was refluxed while ethyl diazoacetate (66 uL, 0.63 mmol) in dichloromethane (1 mL) was added dropwise. After complete addition the reaction was refluxed for 30 minutes and additional ethyl diazoacetate (132 uL, 1.26 mmol) in dichloromethane (1.5 mL) was added dropwise with reflux continuing 30 minutes after complete addition. Solvent was removed in vacuo and die residue purified by HPLC on silica gel eluting with hexane:acetone (3: 1). Fractions containing desired product were pooled, concenttated, dissolved in CC i, and concenttated to constant weight under high vacuum to give the desired product (274 mg) as an oil in 50% yield. IR (CDCI3) 3500, 2930, 1742, 1700, 1645, 1452 cm" 1 ; 13 C NMR (125 MHz) delta 9.4, 11.7, 14.1, 14.2, 15.8, 16.2, 20.5, 21.1, 24.2, 24.6, 26.3, 27.6, 30.3, 30.8, 32.7, 32.9, 33.6, 34.6, 36.4, 39.2, 39.7, 43.1, 48.7, 54.7, 56.3, 56.6, 56.9, 57.2, 60.6, 68.5, 70.1, 72.9, 73.7, 75.2, 77.2, 82.8, 83.6, 97.0, 123.1, 129.6, 132.4, 138.7, 164.7, 169.0, 171.1, 196.1, 213.5; MS (FAB) miz: M+K = 916; Anal, calc'd. for C 4 7H 7 5NOι 4 -1.0 CCI4: C, 54.70; H, 7.33; N, 1.36. Found: C, 54.42; H, 7.22; N, 1.26. configuration). The prior procedure was modified using benzyl diazoacetate instead of ethyl diazoacetate. Ascomycin (0.5 g) provided tide compound (0.1 g) in 20% yield, mp. 65-72 °C; IR (CDCI3) 3510, 2930, 1740, 1695, 1642, 1450 cm" 1 ; I C NMR (125 MHz) delta 9.4, 11.7, 14.1, 15.8, 16.2, 20.4, 21.1, 24.1, 24.5, 26.3, 27.6, 30.3, 30.8, 32.7, 32.8, 34.4, 34.5, 36.3, 39.2, 39.6, 43.1, 48.6, 53.4, 54.6, 56.3, 56.6, 57.1, 66.3, 68.5, 70.1, 72.8, 73.6, 75.1, 76.8, 82.7, 83.6, 96.9, 123.0, 128.3, 128.4, 128.5, 129.5, 132.3, 135.6, 138.7, 164.7, 168.9, 171.0, 196.2, 213.4; MS (FAB) miz: M+H-H 0 = 922, M+K = 978. Anal, calc'd. for C 5 H 7 7NOi4 C, 66.43; H, 8.26; N, 1.49. Found: C, 66.12; H, 8.14; N, 1.41. Example 111: Formula I: R= ethyl: R'= H: n= 1 : Rl= -OCH CrOtOH. The resultant product of Example 110 (25 mg, 0.03 mmol) and 10% Pd/C (3 mg), were placed in a flask and the vessel was flushed with nitrogen for 10 min. Methanol (250 uL) was added via syringe, and the reaction stirred under a hydrogen atmosphere (1 atm) for 45 min. The mixture was filtered, die catalyst washed witii additional methanol (1 mL), and d e solvent removed in vacuo. The resulting residue was partitioned between ethyl acetate (5 mL) and water (5 mL), me organic layer was dried (MgSθ4), filtered and concenttated to constant weight thus producing the tide compound (23 mg) as a white powder. Rl2= NR-HRII; Rli= H: Rl≤= benzyl. The product of Example 111 (849 mg) in DMF (3 mL) was treated with N,N'- carbonyldiimidazole (162 mg) for 5 minutes at room temperature, whereupon benzylamine (107 mg) was added all at once. After 3 hours, the mixmre was partitioned between EtOAc (20 mL) and water (20 mL), and extracted once again with EtOAc (10 mL). The organics were combined, washed with 0.5 N HCl (20 mL) and brine (2 x 20 mL), dried (MgS04), filtered and concenttated to dryness. Purification by chromatography on silica gel eluting witii hexane:acetone (3:1) gave the title compound (568 mg). MS (FAB) miz: (M+K) = 938. Example 113: Formula I: R= ethyl: R'= H: n= 1: Rl= -OO CfO l 2 - CR configuration): RJL2= NR RIS; RI = CHr. Rl^= benzyl. The product of Example 111 is activated as in Example 112 and then treated with N,N- metiiyl,benzylamine instead of benzylamine to provide the title compound. Example 114: Formula I: R= ethyl: R'= H: n= 1 : Rl= -OO CfO^I 2 - (R configuration): RI2= NRiiRl≤; RI =R15= H. The product of Example 111 is activated as in Example 112 and tiien treated witii gaseous ammonia instead of benzylamine to provide the title compound. Example 115: Formula I: R= ethyl: R'= H: n= 1: Rl= -QCHoCfOIRl 2 - (R configuration'): Rl2= NRHRlS; R = H: Rl3= CH 2 . The product of Example 111 is activated as in Example 112 and then tteated with methylamine instead of benzylamine to provide die title compound. RI2= NRHRIS; Rl ^Rl^ CH The product of Example 111 is activated as in Example 112 and then tteated with dimemylamine instead of benzylamine to provide the title compound. Example 117: Formula I: R= ethyl: R'= H: n= 1 : Rl= -OCHoCfO l 2 - (R configuration ' ): Rl2= NR.MR.IS; R14- H: Rl5= ethyl. The product of Example 111 is activated as in Example 112 and then tteated with ethylamine instead of benzylamine to provide the title compound. Example 118: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCHoCfOIRl^ CR configuration'): Rl2= NR-HRIS; Rlά= CBv. Rl≤= ethyl. The product of Example 111 is activated as in Example 112 and tiien tteated witii N,N- methyl,etiιylamine instead of benzylamine to provide die tide compound. Example 119: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH^CfO l^ (R configuration'): Rl2= NRHRLI; Rii= H: Rl≤= -CHoCH^CH^. The product of Example 111 is activated as in Example 112 and then tteated with propylamine instead of benzylamine to provide the title compound. Example 120: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCHoCCOm-l 2 - (R configuration): RI2= NRHRl ; RJ4= c R^= -CH CH C The product of Example 111 is activated as in Example 112 and then tteated with N,N- methyl,propylamine instead of benzylamine to provide the title compound. Example 121: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCHoCfOIRi - (R configuration'): RI2= NRHRIS; R14= H: Rl≤= -CHfCHVb. The product of Example 111 is activated as in Example 112 and then treated witii 2- aminopropane instead of benzylamine to provide the title compound. Example 122: Formula I: R= ethyl: R'= H: n= 1 : Rl= -OCT CfσiR-l. 2 - (R configuration'): Rl2= NRHRIS: Rlά= CHr. Rl5= -CHfOEfa The product of Example 111 is activated as in Example 112 and tiien tteated with N,N- methyl,l-memyletiιylamine instead of benzylamine to provide the title compound. Example 123: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCT CfO Rl - (R configuration'): Rl2=; NRMRI≤; RlA= H: Rl≤= cvclopropyl The product of Example 111 is activated as in Example 112 and then tteated witii cyclopropylamine instead of benzylamine to provide the title compound. Example 124: Formula I: R= ethyl: R'= H: n= 1 : Rl= -OOfrCfO -l - (R configuration): Rl2= NRHRII; R!4= H: Rl5= -CΗoCHoCH αh. The product of Example 111 is activated as in Example 112 and tiien tteated with n-butylamine instead of benzyl amine to provide die title compound. Example 125: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH2C(OtR-1 (R configuration): RI2= NRHRIS; RJ4= CRV. Rl5= -CHoCfoαfrOh. The product of Example 111 is activated as in Example 112 and then tteated with N,N- methylbutylamine instead of benzyl amine to provide the title compound. Example 126: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCTbCCO'lRl - (R configuration ' ): The product of Example 111 is activated as in Example 112 and tiien treated with isobutylamine instead of benzylamine to provide die tide compound. Example 127: Formula I: R= ethyl: R'= H: n= 1 : Rl= -OCTb OIRl 2 - (R configuration): Rl2= NRHRli; Rl 4 = CHy R^= -CH CHrCH l The product of Example 111 is activated as in Example 112 and tiien tteated with N,N- methyl,isobutyIamine instead of benzylamine to provide die tide compound. Example 128: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH2C(O) l (R configuration): Rl2= NRHRJ ; RM= H: R-L5= cvclobutyl. The product of Example 111 is activated as in Example 112 and then tteated witii cyclobutylamine instead of benzylamine to provide die title compound. Example 129: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH2Crθ')Rl2 CR configuration'): Rl2= NR- Rl^: Rl4= H: Rl5= -CHQCHΪCHOCHΪCH*. The product of Example 111 is activated as in Example 112 and tiien tteated witii pentylamine instead of benzylamine to provide die title compound. Example 130.: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH CHRlZ (R configuration'): Rl2= NRI4R15: Rl4= Oh: R^= -CT2 CH 2 CH 2 CH 2 H 2- The product of Example 111 is activated as in Example 112 and then tteated with N,N- methyl,pentylamine instead of benzylamine to provide the title compound. Example 131: Formula I: R= ethyl: R'= H: n= 1: Rl= -OO fO l 2 - (R configuration'): RI2= NR14R1 ; Rte= H: Rl≤= -CH^CH^CHofCHVb. The product of Example 111 is activated as in Example 112 and then tteated with 3- methylbutylamine instead of benzylamine to provide the title compound. Example 132: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCHTCfC tt (R configuration ' ): Rl2= NR Rl^: R 4 ^ CH R^= -CHoCfoCHofGH o. The product of Example 111 is activated as in Example 112 and tiien treated witii N,N- methyl,3-methylbutylamine instead of benzylamine to provide the title compound. Example 133: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH C(O') l2. (R configuration'): Rl2= NRMRI ; R14= H: Rϋ= cvclopentyl. The product of Example 111 is activated as in Example 112 and then treated with cyclopentylamine instead of benzylamine to provide die title compound. Example 134: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH^C^Rl 2 - (R configuration): RI2= NR- Rl ; Rl4= H: R-L5= -CH2CH CH2CH CH2CH . The product of Example 111 is activated as in Example 112 and tiien tteated witii n-hexylamine instead of benzylamine to provide the title compound. Example 135: Formula I: R= ethyl: R'= H: n= 1 : Rl= -OC^CfO^l 2 - (R configuration'): Rl2= NRl Rϋ: Rl4= CHr R^= -CH2CH2CH2CH2CH2CH . The product of Example 111 is activated as in Example 112 and then tteated with N,N- methyl,hexylamine instead of benzylamine to provide the tide compound. Example 136: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCfoCfO'lR-l - (R configuration'): RI2= NR-HR-IS; R = H: Rl≤= cvclohexyl. The product of Example 111 is activated as in Example 112 and tiien tteated with cyclohexylamine instead of benzylamine to provide the tide compound. Example 137: Formula I: R= ethyl: R'= H: n= 1: Rl= -QCH CfO'tRil (R configuration'): Rl2= NRiiRlS; where Rl4 and R& taken together -CH2CH2QCH2CH2-. thus forming a six membered ring incorporating the nitrogen to which they are attached. The product of Example 111 is activated as in Example 112 and tiien treated with morpholine instead of benzylamine to provide me tide compound. Example 138: Formula I: R= ethyl: R'= H: n= 1: R±= -OCHoCfO'lRl 2 - (R configuration'): Rl2= NR-HRi ; Rl4= H: Rl≤= -CH2CH2OH. The product of Example 111 (1.02 g) in DMF (4 mL) is tteated with N,N'-carbonyIdiimidazole (194 mg) for 5 minutes at room temperature, whereupon 2-hydroxyethylamine (147 mg) is added all at once. After 6 hours, the mixture is partitioned between EtOAc (50 mL) and water (30 mL), and extracted once again witii EtOAc (10 mL). The organics are combined, washed with 0.5 N HCl (30 mL) and brine (2 x 30 mL), dried (MgSO*), filtered and concenttated to dryness. Purification is performed by chromatography to give the title compound. Example 139: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCTfrCf tR-l 2 - (R configuration): R12= NR-MRii; Rl^ H: Rl5= -CH2CH2CH2OH. The product of Example 111 is activated as in Example 138 and tiien treated with 3- hydroxypropylamine instead of 2-hydroxyethylamine to provide the title compound. Example 140: Formula I: R= ethyl: R'= H: n= 1: Rl= -OOfrCtTflRi 2 - (R configuration): RI2= NRliRlS; Rii= H: RlS= -CH2CH2CH2CH OH. The product of Example 111 is activated as in Example 138 and then treated witii 4- hydroxybutylamine instead of 2-hydroxyemyIamine to provide die title compound. Example 141: Formula I: R= ethyl: R'= H: n= 1: Rl= -OαftCf lRl 2 - (R configuration): Rl2= NRl Rl : Rli= H: Rl≤= -CH9CH2CH2CH2CH2OH. The product of Example 111 is activated as in Example 138 and tiien treated witii 5- hydroxypentylamine instead of 2-hydroxyethylamine to provide die title compound. Example 142: Formula I: R= ethyl: R'= H: n= 1: Rl= -OC^CfOIRl 2 - CR configuration'): Rl2= NRURii; Rl4= H: RlS= -CH2CH NH . The product of Example 111 is activated as in Example 138, and then tteated with 1,2- diaminoethane instead of 1,2-hydroxyethylamine to provide die title compound. Example 143: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH^O R 11 (R configuration ' ): RI2= NRϋRl : Ri4= H: R ^= -CH2CH2CH2NH 2 . The product of Example 111 is activated as in Example 138, and then treated with 1,3- diaminopropane instead of 1,2-hydroxyetiιylamine to provide the title compound. Example 144: Formula I: R= ethyl: R'= H: n= 1: Rl= -0CH2C(O)R& (R configuration'): RI2= NRϋRli; Rl4= H: Rl£= -CH2CH2CH CH2NH2. The product of Example 111 is activated as in Example 138, and then treated with 1,4- diaminobutane instead of 1,2-hydroxyethylamine to provide the title compound. RI2= NR RI ; RI^ H: Rl5= -CH2CH2CH2CH H2NH . The product of Example 111 is activated as in Example 138, and then tteated witii 1,5- diaminopentane instead of 1,2-hydroxyetiιylamine to provide the title compound. Rl2= NR Rl : Rϋ= H: Rl&= -CH2CO2H. The product of Example 111 is activated as in Example 138, and then treated witii glycine instead of 1,2-hydroxyethylamine to provide the tide compound. Example 147: Formula I: R= ethyl: R'= H: n= 1: Rl= -OO CfO'lRi 2 - (R configuration): RI2= NR Rii; Rl4 = H: R-^= -CH2CH CO7H. The product of Example 111 is activated as in Example 138, and then tteated witii 3- aminopropanoic acid instead of 2-hydroxyethylamine to provide the tide compound. Example 148: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH2Crθ')R 2 (R configuration'): Rl2= NR-HRii; Ri^ H: Rl≤= -CHrRl≤')Cθ2H: Rl≤= CH (R configuration'). The product of Example 111 is activated as in Example 138, and then tteated with (R)-2- aminopropanoic acid instead of 2-hydroxyethylamine to provide the title compound. Example 149: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCTbCfO'lRl - (R confi uration'): The product of Example 111 is activated as in Example 138, and then treated with (S)-2- aminopropanoic acid instead of 2-hydroxyethylamine to provide die title compound. Example 150: Formula El: R= ethyl: R'= H: n= 1: R 3 i=R 3 2=R.i2 = H: R34= OH: R3£ and taken together form an oxo group. To a solution of ascomycin (2 g, 2.53 mmol) in dichlorometiiane (13.3 mL) at -78 °C was added died ylamino suffurtrifluoride (3.4 mL, 25.3 mmol) and die reaction was stirred for 20 min. The reaction mixture was added dropwise to ice water (-75 mL), extracted with etiiyl acetate (2 x 100 mL), dried (Na 2 Sθ4), filtered, and concenttated in vacuo to give a yellow foam (2.21 g). The mixmre was purified by silica gel chromatography to give the tide compound (0.23 g). mp 100-105 °C; IR (CDCI3) 3590, 3470, 2930, 1745, 1720, 1690, 1645, 1450 cπr 1 ; 1 ^ NMR (125 MHz) delta 9.3, 11.8, 14.3, 15.8, 16.3, 20.7, 21.0, 24.2, 24.4, 27.6, 27.6, 30.7, 31.2, 32.9, 32.9, 34.1, 34.7, 35.1, 39.1, 39.2, 41.8, 48.6, 55.7, 56.3, 56.3, 56.4, 56.9, 69.4, 73.6, 74.1, 74.3, 75.2, 75.3, 84.2, 96.9, 123.4, 128.0, 131.5, 140.4, 165.6, 169.4, 196.6, 213.3; MS (FAB) miz: M+H = 792, M+K = 830. Anal, calc'd. for C 3 H 69 NOι 2 -0.6 hexane: C, 66.34; H, 9.25; N, 1.66. Found: C, 66.74; H, 8.88; N, 1.67. Example 151: Formula El: R= ethyl: R'= H: n= 1: R21=R22=R = H: R22= OH: R-25 and Re¬ taken together =NR2&: R2S= -NHCrOIOOft. Ascomycin (5.0 g), methylhydrazinocarboxylate (1.1 g), and p-toluenesulfonϊc acid monohydrate (1.2 g) in metiianol (100 mL) were stirred at ambient temperature for 16 hours and concenttated to dryness. The mixmre was purified by chromatography on silica gel eluting with hexane/acetone mixtures to give pure title compound (3.6 g). An analytical sample was recrystallized from methylene chloride and diethyl ether, mp 159-164 °C; IR (CDCI3) 3600, 3500, 3300, 2950, 1745, 1725, 1700, 1642, 1450 cm" 1 ; 13 C NMR (125 MHz) delta 10.2, 12.0, 14.7, 15.4, 15.7, 20.9, 21.2, 24.2, 26.9, 27.1, 28.0, 30.6, 31.1, 31.2, 32.1, 33.5, 34.6, 34.8, 34.9, 38.9, 41.1, 49.0, 49.1, 52.5, 56.2, 56.6, 56.8, 73.1, 73.5, 73.8, 73.9, 75.8, 76.0, 77.2, 84.1, 97.6, 126.3, 129.1, 132.6, 138.5, 155.7, 159.7, 165.0, 168.9, 196.5; MS (FAB) miz: M+H = 864, M+K = 902. Anal, calc'd. for C 5H73N3θι 3 -2.0 H 2 0: C, 60.05; H, 8.62; N, 4.67. Found: C, 60.17; H, 8.24; N, 4.55. Example 152: Formula El: R= ethyl: R'= H: n= 1: R 3 J=R3 =R- = H: R-31= OH: R& and R3≤ taken together =NR2H: R3S= -NHC OOhαh. Example 151 is repeated using ascomycin and substimting ethylhydrazinocarboxylate for methylhydrazinocarboxylate to provide the title compound. Example 153: Formula El: R= ethyl: R'= H: n= 1: R11=R32=R34= H: R23-= OH: R& and R36 Example 151 is repeated using ascomycin and substituting benzylhydrazinocarboxylate for methylhydrazinocarboxylate to provide die title compound. Example 154: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH.nC(G)R } 2. (R configuration): Rl2= NRHRi ; Rl4= H: Rl5= -CH(Rl£)CONHCHfRl£)CONHCH(R.16^C02H: Rlfl= Ri£= CH (R configuration'). The product of Example 111 is activated as in Example 138, and then tteated with D-alaninyl- D-alaninyl-D-alanine instead of 2-hydtoxyethylamine to provide the tide compound. Example 155: Formula V: R= ethyl: R'= H: n= 1: R- and R 4 - taken together form an oxo group: R2= -C(Q)CFy R i=R =R34 = H: R22= t-butyldimethylsilyloxy: R25 and R& taken together form an oxo group: R21= H. The product of Example 14b (0.8 g, 1.0 mmol) in dry DMF (5 mL) is treated with imidazole (0.1 g) and tert-butyldimethylsilyl chloride (0.18 g) until starting material is consumed. The mixmre is then partitioned between water (20 mL) and EtOAc (20 mL). Organic layer is washed with brine (20 mL). Aqueous layers are extracted with EtOAc (2 x 10 mL), organics are combined, dried (MgSθ4), and concenttated to dryness. This residue is dissolved in THF (4 mL) and is added dropwise to a solution of Uthium hexamethyldisilazide (2.2 mmol) in THF (5 mL) at -78 °C and the mixture is stirred for 30 minutes, whereupon 2,2,2-trifluoroethyl trifluoroacetate (0.17 mL, 1.3 mmol) was rapidly added in one portion. After 5 minutes the reaction mixture is partitioned between 5% aqueous HCl (15 mL) and Et 2 0 (15 mL). The aqueous portion is extracted once more with Et 2 0 and the organics are then washed with brine (2 x 10 mL), dried (Na S04), decanted from solids and concenttated to yield the title compound, which is used immediately in the following reaction. See Danheiser, R.L.; Miller, R. F.; Brisbois, R. G.; Park S. Z. J. Org. Chem. 1990, 55, 1959-1964. Example 156: Formula V: R= ethyl: R'= H: n= 1: R 3 - and R 4 - taken together form an oxo group: R2 and R£ taken together= N2: Rll ^ R^- -R-M..: H: R22= t-butyldimethylsilyloxy: R2£ and R26 taken together form an oxo group. (See reference cited in Example 155.). The product isolated in Example 155 is dissolved in acetonitrile ( mL) to which is added water (18 uL), triethylamine (0.21 mL, 1.5 mmol) and methanesulfonylazide (0.28 mL, 3.0 mmol). After stirring at ambient temperamre for 4 hours, the mixture is concenttated to dryness. The residue is partitioned between EtOAc (20 mL) and water (20 mL). The aqueous layer is exttacted again witii EtOAc (20 mL), and the organics are washed with brine (2 x 10 mL), dried (Na Sθ4) and concenttated to dryness. The residue is purified by chromatography on silica gel to provide the title compound. Examples 157a and 157b: Formula IE: R= ethyl: R' = R21 =H: n= 1: taken together with the carbon atoms to which they are attached. R3-2. R3A R^ 4 -. R 3 -^ and R-36 form an isoxazole ring with C-24 and C-22 becoming positions 5' and 3' of die isoxazole ring: and Formula IE: R= ethyl: R'=H: n= 1: R3-l= H: taken together with the carbon atoms to which they are attached. R-32. R2i. RM. R21 and Reform an isoxazole ring with C-24 and C-22 becoming positions 3' and 5' of the isoxazole ring. A solution of the product of Example 12 (1 g), hydroxylamine hydrochloride (0.1 g) and N- methylmorpholine (0.14 g) in isopropanol was stirred at room temperamre overnight, and tiien refluxed for 6 hours. The solvent was removed and the products were purified by silica gel chromatography eluting with 5% methanol in metiiylene chloride. Yield: 0.7 g; MS (FAB) miz: M+K = 825. Example 158: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R2ά, R 2 ^. R^ 8 - and R-22 form a 6'.9'-diaza-benzof glquinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R-&= OH (R configuration'): Rff∑= H. A solution of ascomycin (0.5 g), 1,2,4,5-tetraaminobenzene tettahydrochlori.de (0.9 g) andN- methylmorpholine (1.4mL) in absolute ethanol (11 mL) was refluxed ovemight The solvent was removed, and the intermediate product was purified by silica gel chromatography. MS (FAB) miz: M+K = 932. The intermediate product (0.18 g) and glyoxal (40% in water, 0.06 g) in absolute ethanol (5 mL) was heated at 50 °C for 5 hours. After removal of solvent, the product was purified by silica gel chromatography eluting with 10% isopropanol in methylene chloride. Yield: 0.075 g; MS (FAB) miz: M+NH4 = 933. Examples 159a. 159b and 159c: Formula V: R= allyl: R'= H: n= 1: R- 2 - = R3-L= R22 = R2 = H: R 3 - and R 4 - taken together form an oxo group: R 3 - 3 - and R3 taken together form an oxo group: R25 and R-3-6 taken together form an oxo group: Formula I: R= allyl: R'= H: n= 1: R 2 - = R = H: R 3 - and R - taken together form an oxo group: and Formula El: R= allyl: R'= H: n= 1: R21= H: R22= H: R23- and R^ - taken together form an oxo group: R 3 -^ and R36 taken together form an oxo group. FK-506 (2 g) was oxidized according to the procedure described in Example 48. The products were purified by sihca gel chromatography eluting with 5% acetone in hexanes. Yield: Example 159a, 0.3 g; MS (FAB) miz: M+K = 838; Example 159b, 0.9 g; MS (FAB) miz: M+K = 840; Example 159c, 0.1 g; MS (FAB) m z: M+H = 840. Example 160: Formula IV: R= ethyl: R'=H: n= 1: R - = R-24 = R2! = H: R 3 - and R 4 - taken together form an oxo group: one of R 1 and R 22 - is H and the other is OH: R2^= OH. The tide compound was prepared from the product of Example 48 according to the procedure described in Example 46. MS (FAB) miz: M+H = 792, M+K = 830. Example 161: Formula VE: R= ethyl: R'=H: n= 1: R 2 - = H: R 3 - and R 4 - taken together form an oxo group: one of R21 and R22 j s H and the other is OH: R22= OH: R2i= H: R3 L= H: R22= H: R 3 - 3 - and R 3 - - taken together form an oxo group: R 3 ^ and R 3 ^ taken together form an oxo group: R£ = H The title compound was prepared from the product of Example 14a according to the procedure described in Example 46. MS (FAB) miz: M+K = 828. Example 169: Formula El: R= ethyl: R'=H: n= 1: R3-l= benzyl: taken together with the carbon atoms to which they are attached. R 3 - 2 -. R23-. R-3A R 3 ^ and R 3 ^ form a pyrazole ring. The tide compound is prepared from the product of Example 16 and hydrazine according to the procedure of Example 52. Example 170: Formula El: R= ethyl: R'=H: n= 1: R3-l= H: taken together with the carbon atoms to which they are attached. R22. R-ϋ. R34, R25. and R-36 form a N-methylpyrazole ring. A solution of the product of Example 12 (0.5 g) and metiiylhydrazine (0.044 g) in absolute ethanol (10 mL) was refluxed under nitrogen for 4 hours. Solvent was removed in vacuo, and product (0.3 g) was purified by silica gel chromatography eluting with 2% methanol in dichloromethane. MS (FAB) m z: M+H = 800. Example 171: Formula El : R= ethyl: R'=H: n= 1: R21= H: taken together with die carbon atoms to which they are attached. R2 . R 3 - 3 -. 3 -. R-25 and Reform a N-ethylpyrazole ring. A solution of Example 12, ethylhydrazine oxalate (0.144 g) and N-methylmorpholine (0.128 g) in absolute ethanol (10 mL) was refluxed under nitrogen. Solvent was removed in vacuo, and product (0.325 g) was purified by silica gel chromatography eluting with 2% methanol in dichloromethane. MS (FAB) miz: M+H = 814. Example 172: Formula IE: R= ethyl: R'=H: n= 1: R&= H: taken together with the carbon atoms to which they are attached. R-2 R23-. R3A R 3 ^ and R-26 form a N-f2'-hydroxyethyr)- pyrazole ring. A solution of the product of Example 12 (0.5 g) and hydroxyethylhydrazine (0.0723 g) in absolute ethanol (10 mL) was refluxed under nitrogen. Solvent was removed in vacuo, and product (0.229 g) was purified by sihca gel chromatography eluting with 3% methanol in dichloromethane. MS (FAB) miz: M+H = 830. Example 173: Formula El: R= ethyl: R'=H: n= I: R3-l= H: taken together with the carbon atoms to which they are attached. R3 R 3 - 3 -. R24. R2£ and R-26 form a N-phenylpyrazole ring. A solution of die product of Example 12 (0.5 g) and phenylhydrazine (0.103 g) in absolute ethanol (10 mL) was refluxed under nitrogen. Solvent was removed in vacuo, and product (0.31 g) was purified by silica gel chromatography eluting with 3% methanol in dichloromethane. MS (FAB) miz: M+H = 862. Example 174: Formula El: R= ethyl: R'=H: n= 1: Rl= OH: R23= OH: R24= H: R21= H: taken together with the carbon atoms to which they are attached. R22-. R3 3 -. R-3 -. R^ and R2ά form a N-benzylpyrazole ring. A solution of the product of Example 12 (0.5 g), benzylhydrazine hydrochloride (0.23 g) and N-metiiylmorpholine (0.14 g) in absolute ethanol (10 mL) was refluxed under nitrogen for 4 hours. Solvent was removed in vacuo, and product (0.28 g) was purified by silica gel chromatography eluting with 3% metiianol in dichloromethane. MS (FAB) miz: M+H = 876. Example 175: Formula El: R= ethyl: R'=H: n= 1: R3-l= H: taken together with the carbon atoms to which they are attached. R22. R 3 - -. R . R2i and Reform a N-(2'-phenylethvD- pyrazole ring. A solution of the product of Example 12 (0.5 g), 2-phenylethylhydrazine sulfate (0.234 g) and N-methylmorpholine (0.14 g) in absolute ethanol (10 mL) was refluxed under nitrogen for 4 hours. Solvent was removed in vacuo, and product was purified by silica gel chromatography eluting with 3% metiianol in dichloromethane. Yield: 0.28 g, MS (FAB) miz: M+H = 890. Example 176: Formula El: R= ethyl: R'=H: n= 1: R3-l= H: taken together with the carbon atoms to which they are attached. R 3 - 2 -. R 3 - 3 -. R^ -. R 3 -^ and R 3 -^ form a N-acetylpyrazole ring. The title compound is prepared from the product of Example 12 and acetyl hydrazine according to the procedure of Example 52. Example 178: Formula VE: R= ethyl: R'=H: n= 1: Rl= triethylsilyloxy: taken together with the carbon atoms to which they are attached. R 2 ^. R^2. R^ 8 - and R22 form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of die heterocyclic system: R 1= H: R22= H: R3-3-= triethylsilyloxy: R-34= H: R 3 -^ and R2ά taken together form an oxo group: Rό Q = OH (R configuration): Rf&= H. A solution of the bis-triethylsilylated compound derived in a fashion similar to that of Example 54 (1.0 g) and o-phenylenediamine (0.32 g) in absolute ethanol (7 mL) was refluxed for 4 hours. Solvent was removed in vacuo and product (1.0 g) was purified by sihca gel chromatography eluting with 15% acetone in hexanes. MS (FAB) miz: M+K = 1130. Example 179: Formula IV: R= ethyl: R'=H: n= 1 : R2 = H: R 3 - and R 4 - taken together form an oxo group: taken together with the carbon atoms to which they are attached. R 6. R2Z. R-% 8 - and R2£ form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of die heterocyclic system: R-6Ω and R-65 taken together form an oxo group: R = H. To a solution of oxalyl chloride (0.0465 g) in dry methylene chloride (2 mL) at -70 °C was added dimethylsulfoxide (0.043 g). After stirring at -70 °C for 0.5 hours, a solution of the product of Example 178 (0.2 g) in methylene chloride (2 mL) was added, and die mixmre was stirred for an additional 1.5 hours. Triethylamine (0.15 g) was added, and die cooling bath was removed. After stirring at room temperature for 0.5 hours, the reaction was partitioned between etiier (30 mL) and water (10 mL), the organic phase was washed witii 1 N HCl (3 X 3 mL), dried over magnesium sulfate and solvent removed in vacuo.. The crade intermediate was deprotected according to the procedure described in Example 167 to give the product: 0.15 g; MS (FAB) miz: M+NH4 = 877. Example 180: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration): taken together with the carbon atoms to which they are attached. R-2-6, R27-. R2& and 29- form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: = H: R22= H: R22= t-butyldimethylsilyloxy: R2 = H: R and R≥6 taken together form an oxo group: RάΩ= OH (R configuration'): R&= H. A solution of the product of Example 54 (2.0 g) and o-phenylenediamine (0.628 g) in absolute etiianol (15 mL) was refluxed for 6 hours. Solvent was removed in vacuo and product (1.8 g) was purified by sihca gel chromatography eluting with 15% acetone in hexanes. MS (FAB) miz: M+K = 1130. Example 181: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimetiiylsilyloxy: taken together with the carbon atoms to which they are attached. R26. R2Z. R2& and R22 form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R31= H: R3 = H: R32= t-butyldimemylsilyloxy: R34= H: R 3 -^ and R 3 ^ taken together form an oxo group: R* and R taken together form an oxo group. The tide compound was prepared from the product of Example 180 using the procedure described in Example 179. MS (FAB) miz: M+H = 1090; M+K = 1128. Example 182: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R2& R22. Rig, and R 2 ^ form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R≤Ω= QAc (R configuration'): R6-i= H. To a stirred solution of the product of Example 180 (0.5 g) in dry pyridine (8 mL) containing catalytic amount of dimethylaminopyridine (15 mg) was added acetic anhydride (1.1 mL). After stirring at room temperature for 40 min., the reaction mixmre was partitioned between ether and water. The organic phase was washed witii 0.5 N HCl and brine and dried over magnesium sulfate. Solvent was removed in vacuo to give the acetate as a white foam (0.51 g). 40% Aqueous HF (0.087 mL) in acetonitrile was added over 1 min to a stirred solution of this foam (0.51 g) in acetonitrile (8 mL). The reaction mixture was diluted witii water after 0.5 hours at room temperature and exttacted with ether. The organic phase was washed once with saturated sodium bicarbonate, dried over magnesium sulfate and solvent removed in vacuo. The product was purified by silica gel chromatography eluting with 20% acetone in methylene chloride. Yield: 0.33 g; MS (FAB) miz M+H = 906, M+K = 944. Example 211: Formula VI: R= ethyl: R'=H: n= 1 : taken together with the carbon atoms to which they are attached. R26. R2Z. R2& and R form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of die heterocyclic system: R-3-l= H: taken together with the carbon atoms to which they are attached. R 3 - 2 -, R3i, R3 4 and R-25 form a pyrazole: R-6Ω= OH (R configuration'): R&= H. A solution of the product of Example 52 (0.785 g) and o-phenylenediamine (0.2 g) in absolute ethanol is refluxed under nitrogen overnight. After removal of solvent die product is purified by sihca gel chromatography. Example 212: Formula VI: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which they are attached. R26. R2Z R^ 8 - and R2£ form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R-3ϋL= H: R22= H: R 3 - 3 - and R2 taken together is nitrogen. R 3 -^ and R-3-6 taken together is nitrogen, the two nitrogens are bridged by a phenyl ring to form a benzodiazepine ring: R-6 @ = OH (R configuration! : R65= H. A solution of the product of Example 12 (0.8 g) and o-phenylendiamine (0.4 g) in absolute ethanol (10 mL) is refluxed under nitrogen ovemight After removal of solvent the product is purified by sihca gel chromatography. Examples 213a and 213b: Formula IE: R= ethyl: R'=H: n= 1: R3-l= H: R3-6= O such that when taken together with R 3 - 2 -. R 3 - 3 -. R ^. R -^. and the carbon atoms to which they attached form a furan with a carboethoxy attached at the alpha position: and Formula IE: R= ethyl: R'=H: n= 1: R21= H: R23= O wuch that taken together with R-22- R . R25. R26 and the carbon atoms to which they attached form a furan with a carboethoxy attached at alpha position. The title compounds are prepared from the product of Example 12, ethyl diazoacetate and rhodium acetate according to the methods described in the literature (Paulissen, R., et al, Tetrahedron Lett., 1974, 607). Examples 214a and 214b: Formula El: R= ethyl: R'=H: n= 1: R 3 -! and R22 taken together form a bond: taken together with the carbon atoms to which tiiey are attached. R-24= O. and R 3 - 2 - form a furan substituted with hydroxymethyl group at the alpha position: R3-5 and R2ό taken together form an oxo group: and Formula El: R= ethyl: R'=H: n= 1: R -! and R 3 -^ taken togedier form a bond: taken together with the carbon atoms to which thev are attached. R3-&= O and whentaken together with R22 forms a furan substituted with hydroxymethyl group at the alpha position: R2 - and R^ - taken together form an oxo group. The tide compounds are prepared from the product of Example 12 and epoxyacrolein according to the metiiods described in the literature (Williams, P.H., et al, J. Am. Chem. Soc. 1960, 82, 4883). Example 215: Formula IE: R= ethyl: R'=H: n= 1: R21= H: R-23- = N R 3 ^ and R3 4 taken together form a bond. R 3 ^ and R2ά taken together = N. such that taken together with the carbon atoms to which they attached R 3 -!. R-32. R23-. RM. R2.I, R3ϋ form a pyrimidine with a phenyl group attached at a position 2'. A solution of the product of Example 12 (0.8 g), benzamidine hydrochloride (0.4 g) and N- methylmorpholine (0.5 g) in isopropanol (10 mL) is refluxed for 2 hours. After removal of solvent the product is partitioned between ethyl acetate and water. The organic phase is washed once with brine, dried over magnesium sulfate and the solvent is removed in vacuo. The product is purified by sihca gel chromatography. Example 216: Formula IE: R= ethyl: R'=H: n= 1: 23- and R^ - taken together form an oxo group: R3-l= H: R22= o-nitrophenyl: 25 and R-36 taken together form an oxo group. The tide compound is prepared from die product of Example 12 and l-fluoro-2-nittobenzene according to the procedure described in Example 16. Examples 217a and 217b: Formula El: R= ethyl: R'=H: n= 1 : R-21 and R23- taken together form a bond: taken together with the carbon atoms to which they are attached. R24= NH. and R-32 form an indole: R-25 and R 3 -^ taken togedier form an oxo group: and Formula IE: R= etiiyl: R'=H: n= 1: R31 and Retaken together form a bond: taken together with the carbon atoms to which they are attached. R26= NH. and R 3 - 2 - form an indole: R33- and R-2- 4 - taken together form an oxo groμp. The product of Example 216 and a catalytic amount of 5% PdC in ethanol is stirred under 1 arm of hydrogen. The reaction is followed by TLC analysis. The catalyst is then filtered off, solvent removed and product piirified by silica gel chromatography. Examples 218a and 218b: Formula El: R= ethyl: R'=H: n= 1: R21= H: R32 and Refor a bond: R26= N. R 3 - 3 - and R^ -. taken together with die carbon atoms to which they attached form a pyridine with amino group at position 2' and cyano group at position 3': and Formula IB: R= ethyl: R'=H: n= 1: R21= H: R22 and RSi-form a bond: R32= N. R3A and R3ά. taken together with the carbon atoms to which they attached form a pyridine with amino group at position 2' and cvano group at position 3'. The tide compounds are prepared from the product of Example 12 according to the methods described in the literature (Troschutz, R.; Troschutz, I.; Sollhuberkretzer, M. Arch. Pharm. 1985, 777-781). Examples 219a and 219b: Formula I: R= ethyl: R'=H: n= 1: R - = H: R2= OH: R4= methyl: R21 = H: and Formula I: R= ethyl: R'=H: n= 1 : R 2 - = H: R-4= OH: R2= methyl: R21 = H. Methylmagnesium chloride (0.3 mL, 3 M in THF) is added into a stirred solution of die product of Examplel2 (0.8 g) in dry THF (100 mL) at -70 °C. After stirring at -70 °C for 8 hours, the reaction mixture is partitioned between ether and 1 N HCl. The organic phase is washed once with brine and solvent removed. The products are purified by silica gel chromatography. Example 220: Formula I: R= ethyl: R'=H: n= 1: R 4 - and R - taken together form a bond: R-2= methyl: R21 = H. A solution containing the products of Examples 219a and 219b and sihca gel in methylene chloride is stirred at room temperamre ovemight The sihca gel is filtered off, solvent removed and product purified by silica gel chromatography. Example 221: Formula El: R = ethyl: R' = H: n = 1: R = R32 = R = H: R-23- = hvdroxy: R25 and R& taken together form a hvdrazone. =NR3& where RS& = -NHSfO'bR 4 ^ and R4Ω = 4-methylphenyl. Ascomycin (1.00 g, 1.26 mmol) was dissolved in ethanol (125 mL) and tteated at room temperamre ovemight withp-toluenesulfonyl hydrazide (235 mg, 1.26 mmol) andp- toluenesulfonic acid monohydrate (240 mg, 1.26 mmol). The solvent was removed under reduced pressure, and the crude material was purified by flash chromatography on silica gel eluting with 40% acetone in hexane. The title compound was obtained as a colorless sohd (431 mg): mp 193-194 °C; IR (CDCI3) cm- 1 3500, 2940, 1745, 1720, 1650, 1455, 1170, 1090; i H NMR (CDCI3, 500 MHz) delta (selected peaks) 9.21 & 9.18 (br s, 1 H total), 7.83 (m, 2H), 7.30 (m, 2 H), 3.44 (s, 3 H), 3.36 (s, 3 H), 3.27 (s, 3 H); MS (FAB) mle: M+K = 999. Example 222: Formula IV: R = ethyl: R' = H: n = 1: Rl = -NR-HCfO)RJ£ (S configuration) where R-12 = H and Rl& = phenyl: R 2 ^. R2 and the carbon to which they are attached are absent: one of R2& and R 2 ^ is hydroxy and the other is -COOH: C-8 is directly attached to C- 10: RόΩ = hvdroxy (R configuration): R&= H. The product of Example 5 (538 mg, 0.600 mmol) is dissolved in THF-H 2 0 (15 mL, 5:1) and tteated at 0 °C with litiiium hydroxide monohydrate (26 mg,0.618 mmol) for 2 hours. The reaction is permitted to warm to ambient temperature and monitored by TLC (40% acetone in hexane) until complete. The reaction mixmre is then quenched with 1 N HCl (625 uL). This is diluted with additional water, and exttacted witii CH C1 . The combined organic washes are dried and freed of solvent to yield die title compound. Example 223: Formula IV: R = ethyl: R' = H: n = 1: Rl = -ΝRi2C(Q)Rl≤ (S configuration') where R-12 = H and Rl 8 - = phenyl: R 2 !. R22 and the carbon to which they are attached are absent: C-8 is directly attached to C-10: R23- = hydroxy- 24 - = H. The material obtained in Example 222 (490 mg,0.576 mmol) is dissolved in benzene to which lead tettaacetate (258 mg, 0.582 mmol) is added. After 2 hours, the mixmre is quenched with NaHC0 3 (aq) and exttacted witii CH 2 C1 . The combined organic washes are washed witii water, dried over magnesium sulfate, and concenttated in vacuo. The crade material is purified by flash chromatography with acetone-hexane as eluent. Examples 224a and 224b: Formula IE: R = ethyl: R' = H: n = 1: R 3 -! and R23- taken together form a bond: R-22 = H: R 34 = H: R3i= H and R3-i= QH: and Formula El: R = ethyl: R' = H: n = 1 : R-21 and R-23- taken together form a bond: R22 = H: R = H: R21= OH and R2&= H The product of example 36 (861 mg, 1.11 mmol) was dissolved in metiianol (75 mL) to which was added CeCl 3 »7 H 2 0 (456 mg, 1.22 mmol). The resultant mixture was chilled to 0 °C, and sodium borohydride (46 mg, 1.22 mmol) was added portionwise. After 1 hour, the reaction was quenched by pouring the reaction mixmre into 75 mL of water. This mixture was exttacted witii ether (2 x 50 mL). The combined organic extracts were dried over magnesium sulfate and freed of solvent The isomeric allylic alcohols were purified and separated by sihca gel chromatography using 25% acetone in hexane as eluent Those fractions containing pure higher and lower Rf alcohols respectively were combined to furnish the less polar allylic alcohol (0.12 g) and die more polar allylic alcohol (0.23 g). Example 224a: *H NMR (CDC1 3 , 500 MHz) delta (selected peaks) 5.65 (ddd, J = 8.75, 16, 67.5 Hz, 1 H), 3.43 (s, 3 H), 3.38 (s, 3 H), 3.32 (s, 3 H), 1.67 (s, 3 H), 1.63 (s, 3H), 1.06 (d, J = 7.5 Hz, 3 H), 0.84 (t J = 7.5 Hz, 3 H). Example 224b: IR (CDCI3) cm' 1 3440, 2930, 1740, 1650, 1450, 1090; *H NMR (CDCI3, 500 MHz) delta (selected peaks) 5.45 (ddd, / = 6.5, 17.5, 42.5 Hz, 1 H), 1.66 (s, 3 H), 1.64 (s, 3 H), 1.04 (d, J = 7.5 Hz, 3 H), 0.99 (d, / = 7.5 Hz, 3 H), 0.87 (d, / = 7.5 Hz, 3 H), 0.83 (t, J= 7.5 Hz, 3 H); MS (FAB) mie: M+K = 814. Example 225: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration): R21= H: R22= R 3= QH: R 4= H: R23= t-butyldimethylsilyloxy: R3i= R32= R2 = H: R 3 -^ and R2£ taken together form an oxo group. The title compound is prepared according to die procedures described in die published European patent application of Sandoz, No.0402931 Al, Example 1. Example 226: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration-): R22= H: R21= R23= OH: R24= H: R22= t-butyldimethylsilyloxy: R3i= R-22= R3-4= H: R-3-5 and R 3 ^ taken together form an oxo group. The title compound is prepared according to die procedures described in the published European patent application of Sandoz, No.0402931 Al, Example 2. Example 227: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (7? configuration'): R22= H: R21= R22= OH: R24= H: R33= t-butyldimethylsilyloxy: R-21= R3-2= R2 = H: R 3 -^ and Retaken together form an oxo group. A solution of triphenylphosphine (0.131 g) and diethyl azodicarboxylate (0.09 g) in dry tetrahydrofuran (THF, 2 mL) is added to a stirred solution of the product of Example 225 (0.45 g) in THF (10 mL) followed by a solution of diphenylphosphorylazide (0.14 g in 1 mL of THF). The reaction mixture is stirred at 45 °C and the progress is monitored by TLC analysis. The reaction is quenched witii water and exttacted witii ethyl acetate. Solvent is removed and the product is purified by silica gel chromatography. Example 228: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration'): R21= H: R22= o-nitrobenzenesulfonate: R22= OH: R2ά= H: R32= t- butyldimethylsilyloxy: R21= R22= R = H: R35 and R 3 -^ taken together form an oxo group. o-Nittobenzenesulfonyl chloride (0.115 g) in dry methylene chloride (1 mL) is added into a stirred solution of the product of Example 225 (0.5 g) and trietiiylamine (0.1 g) in methylene chloride (5 mL) at room temperature. After stirring at room temperature overnight the solvent is removed and the product purified by sihca gel chromatography. Example 229: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration): R21= N = H: R22= QH: R24= H: R33= t-butyldimethylsilyloxy: R21= R22= R3J H: R.25. and R-26 taken together form an oxo group. Sodium azide (0.1 g) is added into a stirred solution of the product of Example 228 (0.12 g) in dry DMF (1 mL) at room temperature and heated at 60 °C for 5 hours. The reaction mixture is partitioned between ether and water. The organic phase is washed once with brine, dried over magnesium sulfate and die solvent is removed. The product is purified by sihca gel chromatography. Example 230: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (7? configuration'): R21= H: R22= Ny R = OH: R24= H: R23= t-butyldimethylsilyloxy: R-21= R32= R24= H: R35 and R-26 taken together form an oxo group. The tide compound may be prepared according to the procedures described in Examples 227 or 229, but replacing the product of Example 225 with that of Example 226. Example 231: Formula E: R= ethyl: R'=H: n= 1: R22= H: R21= Ny R23-= OH: R24= H. 40% Aqueous HF (0.1 mL) in acetonitrile (5 mL) is added into a stirred solution of die product of Example 227 (0.4 g) in acetonitrile (8 mL) at room temperamre. The reaction mixmre is diluted with water after stirring 2 hours at room temperature and exttacted witii ether. The organic phase is washed once witii brine, dried over magnesium sulfate, and the solvent is removed. The product is purified by silica gel chromatography. Example 232: Formula E: R= ethyl: R'=H: n= 1: R21= H: R22= Ny R = QH: R24= H. The tide compound may be prepared according to the procedure described in Example 231 , but replacing the product of Example 227 with tiiat of Example 230. Example 233: Formula E: R= ethyl: R'=H: n= 1: R22= H: R21= NH : R = OH: R24= H. A solution of the product of Example 231 (0.25 g) and triphenylphosphine (0.09 g) in wet toluene (10 mL) is stirred at 70 °C for 8 hours. The solvent is removed and die product is purified by preparative TLC on sihca Example 234: Formula E: R= ethyl: R'=H: n= 1: R22= NH R2 = H: R 2= QH: R i= H. The tide compound may be prepared according to the procedure described in Example 233, but replacing the product of Example 231 with that of Example 232. Example 235: Formula E: R= ethyl: R'=H: n= 1: R2 = H: R21= NHAC: R22= QH: R24= H. Acetic anhydride (0.15 g in 1 mL of dry methylene chloride) is added into a stirred solution of the product of Example 233 (0.4 g) containing triethylamine (0.15 g) in methylene chloride, (5 mL) and die mixture is stirred at room temperature for 1 hour. The reaction mixture is partitioned between ether and 1 N HCl. The organic phase is washed once witii brine, dried over magnesium sulfate and solvent removed. The product is purified by sihca gel chromatography. Example 236: Formula E: R= ethyl: R'=H: n= 1: R21= H: R22= NHAc: R22= OH: R24= H. The tide compound may be prepared according to the procedure described in Example 235, but replacing the product of Example 233 with that of Example 234. Example 237: Formula E: R= ethyl: R'=H: n= 1: R2 = H: R21= NH-adamantanecarbonyl: R23= OH: R2 4 =H. The tide compound may be prepared according to the procedure described in Example 235 by replacing acetic anhydride witii 1-adamantane carbonyl chloride. Example 238: Formula E: R= ethyl: R'=H: n= 1: R21= H: R22= NH-adamantanecarbonyl: RΩ= QH: R2ά=H. The title compound may be prepared according to the procedure described in Example 236 by replacing acetic anhydride witii 1-adamantane carbonyl chloride. Example 239: Formula II: R= ethyl: R'=H: n= l: R22= H: R21= benzoylamido: R 1= OH: R 24 = H. The title compound may be prepared according to the procedure described in Example 235 by replacing acetic anhydride with benzoyl chloride. Example 240: Formula II: R= ethyl: R'=H: n= 1: R21= H: R22= benzoylamido: R22= QH: R2 4 = H. The title compound may be prepared according to die procedure described in Example 236 by replacing acetic anhydride witii benzoyl chloride. Example 241: Formula E: R= ethyl: R'=H: n= l: R22= H: R21= N-benzylamino: R23= OH: R24= H Benzyl bromide (0.1 g) is added into a stirred solution of the product of Example 233 (0.4 g) in acetonitrile (5 mL) at 0 °C. After being stored at 0 °C overnight the reaction mixmre is refluxed for an additional hour. The product is purified by sihca gel chromatography. Example 242: Formula E: R= ethyl: R'=H: n= 1: R21= H: R22= N-benzylamino: R-22= OH: R24= H. The title compound may be prepared from benzyl bromide according to the procedure described in Example 241 , but replacing the product of Example 233 with that of Example 234. Example 243: Formula E: R= ethyl: R'=H: n= 1: R21= N-rf4'.5'-biscarboethoxy')-ttiazolel: R22= H: R2a= OH: R2 4 = H A mixmre of the product of Example 231 (0.4 g) and dietiiylacetylene dicarboxylate (1 mL) is stirred at room temperature overnight The triazole is purified by silica gel chromatography. Example 244: Formula E: R= ethyl: R'=H: n= 1: R21= H: R22= N-r(4 , .5 , -dicarboethoxyV triazolel: R2 = OH: R24= H. The tide compound may be prepared according to the procedure described in Example 243, but replacing the product of Example 231 witii the that of Example 232. Example 245: Formula E: R= ethyl: R'=H: n= 1: R2 = N-rr2'.5'-dimethylVpyrrole1: R22= H: R22= QH: R2 = H. A solution of acetonylacetone (0.5 g) and the product of Example 233 (0.5 g) in absolute ethanol (5 mL) is refluxed for 6 hours. After removal of solvent, the product is purified by silica gel chromatography. Example 246: Formula π: R= ethyl: R'= H: n= 1: R21= H: R22= N-rf2'.5'-dimethylVpyrrole1: R2a= OH: R2 4 = H. The tide compound may be prepared from acetonylacetone according to the procedure described in Example 245, but replacing the product of Example 233 with tiiat of Example 234. Example 247: Formula VE: R= ethyl: R'=H: n= 1 : Rl= t-butyldimethylsilyloxy (R configuration'): R22= H: R21= iodo: R2^= OH: R24= H: R22= t-butyldimethylsilyloxy: R31= R32= R24= H: RSI and R-3& taken together form an oxo group. Potassium iodide (0.1 g) is added into a stirred solution of the product of Example 228 (0.13 g) in dry DMF (1 mL) at room temperature and heated at 70 °C for 4 hours. The reaction mixture is partitioned between ether and water. The organic phase is washed once with brine, dried over magnesium sulfate and solvent removed. The product is purified by sihca gel chromatography. Example 248: Formula E: R= ethyl: R'=H: n= 1: R2I= iodo: R = H: R22= OH: R2 = H. The product of Example 247 may be deprotected according to die procedure of Example 231 to give the title compound. Example 249: Formula E: R= ethyl: R'=H: n= 1 : R21= H: R22= iodo: R22= QH: R2 = H. The title compound may be prepared according to the procedure of Examples 228, 247 and 248, but replacing the product of Example 225 with tiiat of Example 226. Example 250: Formula E: R= ethyl: R'=H: n= 1: R21= bromo: R22= H: R22= OH: R24= H. The tide compound may be prepared according to die procedure of Examples 247 and 248, but replacing potassium iodide with potassium bromide. Example 251: Formula E: R= ethyl: R'=H: n= 1: R21= H: R2 = bromo: R22= OH: R2i= H. The tide compound may be prepared according to the procedure of Example 249, but replacing potassium iodide witii potassium bromide. Example 252: Formula VE: R= ethyl: R'=H: n= 1: Rl= t-butyldimethylsilyloxy (R configuration'): R22= H: R21=thiomethoxy: R22= OH: R^= H: R3^= t-butyldimethylsilyloxy: R3JL= R3 = RSfts H: Rβi. and R-3& taken together form an oxo group. Sodium thiomethoxide (0.1 g) is added into a stirred solution of the product of Example 228 (0.12 g) in dry DMF (1 mL) at room temperamre for 5 hours. The reaction mixture is partitioned between ether and water. The organic phase is washed once with brine, dried over magnesium sulfate and solvent removed. The product is purified by sihca gel chromatography. Example 253: Formula II: R= ethyl: R'=H: n= 1: R22= H: R21= diiomedioxy: R22= OH: R24= EL The product of Example 252 is deprotected according to the procedure of Example 231 to give the title compound. Example 254: Formula II: R= ethyl: R'=H: n= 1: R21= H: R22= diiomedioxy: R22= OH: R24= IL The tide compound may be prepared according to die procedure of Examples 228, 252 and 253, but replacing the product of Example 225 with that of Example 226. Example 255: Formula VE: R= ethyl: R'= H: n= 1: Rl= tert-butyldimethylsilyloxy (R Configuration): R21 and 22 taken together form an oxo group: R22 and R 2 - taken together form a bond: R31= H: R22= H: R22= tert-butyldimethylsilyloxy: R34= H: R-25 and R& taken together form an oxo group. The product of Example 54 (407.8 mg, 0.4 mmol) was dissolved in 4 mL of pyridine at 0 °C, and tiiionyl chloride (46.8 uL, 0.6 mmol) was added. It was tiien stirred at 0 °C for 15 min and at room temperature for 72 hours. Ethyl acetate (40 mL) was added to the reaction mixmre, and die organic layer was washed witii brine, 10%-KHSθ4, brine and tiien dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 364 mg of crade product which was purified by silica gel (50 g) column chromatography, eluting 2.5%-ethyl acetate in chloroform. Yield: 168.7 mg of pure title compound was isolated. MS (FAB) miz: M+K = 1040. Example 256: Formula II: R= ethyl: R'= H: n= 1: R21 and R22- taken together form an oxo group: R23- and R 24 - taken together form a bond. The product of Example 255 (120 mg, 0.12 mmol) was dissolved in 2.5 mL of acetonitrile and 48% hydrofluoric acid (100 uL) was added. It was tiien stirred at room temperature for 1 hour. Ethyl acetate (30 mL) was added to the reaction mixmre, and die organic layer was washed with brine, 10%-NaHCθ3, brine and tiien dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 98.2 mg of crade product which was purified by silica gel (25 g) column chromatography, eluting with 1.5%-methanol in chloroform. 63.4 mg of pure tide compound was isolated. MS (FAB) miz: M+K = 812. Ascomycin (500 mg, 0.632 mmol) was dissolved in 6 mL of benzene in an ice bath, and triediylamine (264 uL, 1.9 mmol) followed by diphenylchlorophosphate (393 uL, 1.9 mmol) in benzene (5 mL) was added dropwise. After 4-Dimemylaminopyridine (DMAP) (100 mg, 0.82 mmol) was added, it was tiien stirred at room temperamre for 1 hour. 10%-Sodium bisulfate (5 mL) was added to the cooled reaction mixture. After additional benzene (20 mL) was added, the organic layer separated was with 10%-NaHCO 3 (40 mL x 3), brine (x5) and then dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 860 mg of crude product which was purified by flash sihca gel (120 g) column chromatography, eluting with 25%-acetone in hexane. 656 mg of pure tide compound was isolated. MS (FAB) miz: M+K = 1294. Example 258: Formula E: R= ethyl: R'= H: n= 1: R21 and RSI taken together form an oxo group: R22= CfiHsOftO: R 24 ^ H. The tide compound is prepared from die product of Example 19 (85 mg, 0.1 mmol), silver trifluoromethanesulfonate (28.3 mg, 0.11 mmol) and disodium hydrogen phosphate (14.2 mg, 0.1 mmol) in 1 mL of benzene and 1 mL of benzyl alcohol. After 2 hours, the mixture is quenched witii 10%-NaHCθ3 and exttacted with etiiyl acetate. The combined organic layers are washed with brine, dried over magnesium sulfate, and concenttated in vacuo. The crade material is purified by sihca gel column chromatography eluting witii 20% acetone-hexane. Example 259: Formula I: R= ethyl: R'= H: n= 1: Rl= H. The product of Example 11 (447 mg, 0.48 mmol) was dissolved in toluene (6 mL) and deoxygenated with nitrogen for 10 min.2,2'-azo-bis(2-methylpropanittile)(15.8 mg, 0.096 mmol) and tributyltin hydride (196 uL, 0.72 mmol) were added, and die mixmre was warmed to 75 °C for 3 hours with stkring. Ethyl acetate (40 mL) was added to die reaction mixture, and die organic layer was washed witii brine, 10%-KHSθ4, brine, 10%-NaHCθ3, brine, and tiien dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 421 mg of crade product Purification was carried out using silica gel column chromatography, eluting 10%- ethyl acetate in chloroform. 28 mg of pure title compound was isolated. MS (FAB) miz: M+K = 814. IR(KBr); 3500, 3460, 2950, 2920, 2860, 2840, 2820, 1740, 1715, 1690, 1645, 1460, 1450, 1440, 1410, 1375, 1350, 1340, 1310, 1280, 1260, 1245, 1190, 1170, 1150, 1140, 1100, 1090, 1070, 1040, 1020, 1010. Rl2 ^ = NRHRII; where Rl 4 - and Rl5 taken together = -C C C C -. thus forming a five membered ring incorporating the nitrogen to which they are attached. The product of Example 111 is activated as in Example 112 and tiien treated witii pyrrolidine instead of benzylamine to provide the tide compound. Example 261: Formula I: R = ethyl: R' = H: n = 1: Rl= -OCH2 fO)Rl2 CR configuration): R.L = NR- Rl ; where RJ 4 - and Rl5 taken together = -CHoCHo ΗoCH^H?-. thus forming a six membered ring incorporating the nitrogen to which they are attached. The product of Example 111 is activated as in Example 112 and then treated witii piperidine instead of benzylamine to provide the title compound. Example 262: Formula IV: R = ethyl: R' = H: n = 1: Rl= CfiHsC(Q)NH (S Configuration): R21. R22 and the carbon to which they are attached form a diastereomeric pair of epoxides: R23- = OH: R24 = H. The product of Example 5 (1.13 g, 1.26 mmol) is dissoloved in methylene chloride (100 mL) and treated with diazomethane (8.4 mL, 2.5 mmol, ~0.3 M in Et 0) at ambient temperamre. TLC analysis (acetone/hexane, 2:3) is used to monitor the progress of the reaction. An additional equivalent of diazomethane is added every few hours until die reaction was judged to be complete. Excess reagent is removed by gently bubbling a stream of nitrogen through the reaction mixmre, and then the volatiles are removed under reduced pressure. The products are separated and purified by flash chromatography (ethyl acetate, 300 g sihca) to supply the major and die minor diastereomers. Example 263: Formula I: R= allyl: R'= H: n= 1: Rl= H. The tide compound may be prepared according to die procedures described in Examples 11 and 259, using FK-506 in place of ascomycin. Example 264: Formula I: R= ethanalyl: R'= H: n= 1: Rl= H. A solution of osmium tettoxide (1 mL of a 4% solution in water) is added into a stirred solution of the title compound of Example 263 (1.4 g) and 4-methylmorpholine N-oxide (1.4 g) in THF (25 mL) and water (15 mL) at room temperamre. The reaction mixture is stirred at room temperamre for an additional 4 hours. After addition of sodium metabisulfite, the reaction mixmre is partitioned between water and ethyl acetate. The organic phase is washed witii brine, dried over magnesium sulfate and solvent is removed. The residue is redissolved in benzene (40 mL) and lead tettaacetate (1.4 g) is added. After stirring at room temperamre for 4 min., the reaction mixmre is diluted witii etiier and the precipitate is filtered off. The solution is filtered through sihca gel (5 g) with ether elution. After removal of solvent, the product is purified by sihca gel chromatography. Example 265: Formula I: R= carboxymethyl: R'= H: n= 1: Rl= H. A solution of the product of Example 264 (0.8 g) in ethanol (5 mL) is added into a suspension of 10% Pd/C (0.1 g) in etiianol (10 mL). Ah is bubbled tiirough the stirred reaction mixmre for 96 hours, and the sohd is removed by filtration. After removal of solvent the product is purified by sihca gel chromatography. Example 266: Formula I: R= methyl carboxymethyl: R r = H: n= 1 : Rl= H. A solution of diazomediane in etiier is added into a stirred solution of the product of Example 265 (0.5 g) in methylene chloride (5 mL) until no starting material is present A few drops of glacial acetic acid are added and die reaction mixmre is straed for 0.5 hours. Solvent is removed and die product is purified by sihca gel chromatography. Example 267: Formula I: R= N-morphohne-amidomethyl: R'= H: n= 1: Rl= H. A solution of the product of Example 265 (0.2 g), morpholine (0.06 g), l-ethyl-3-(3- dimethyl.ammopropyl)carbodiimide hydrogen chloride (0.06 g) and 4-dimemylanιinopyridine (0.06 g) in dry methylene chloride (4 mL) is stirred at room temperature overnight The reaction mixture is partitioned between water and methylene chloride. After removal of solvent, the product is purified by sihca gel chromatography. Example 268: Formula I: R=N-beta-hydroxyethylamidomethyl: R'= H: n= 1: Rl= H. The tide compound may be prepared from the product of Example 265 and ethanolamine according to the procedure described in Example 267. Example 269: Formula I: R= carboxymethyl. amide with glycine methyl ester: R'= H: n= 1 : Rl= H. The title compound may be prepared from the product of Example 265 and glycine methyl ester according to the procedure described in Example 267. Example 270: Formula I: R= N-piperidine-amidomethyl: R'= H: n= 1: Rl= H. The title compound may be prepared from the product of Example 265 and piperidine according to the procedure described in Example 267. Example 271: Formula I: R= N-benzylamidomethyl: R'= H: n= 1: Rl= H. The tide compound may be prepared from me product of Example 265 and benzylamine according to die procedure described in Example 267. Example 272: Formula I: R= N-n-butylamidomethyl: R'= H: n= 1: Rl= H. The tide compound may be prepared from the product of Example 265 and n-butylamine according to the procedure described in Example 267. Example 273: Formula I: R= phenylcarboxymethyl: R'= H: n= 1: Rl= H. The title compound may be prepared from die product of Example 265 and excess phenol according to die procedure described in Example 267. Example 274: Formula I: R= 2-oxopropyl: R'= H: n= 1 : Rl= H. A mixmre of palladium (E) chloride (0.05 g) and copper (I) chloride (0.1 g) in DMF (10 mL) and water (2 mL) is oxygenated by bubbling air through the mixmre for 0.5 hours. A solution of the product of Example 263 (0.2 g) in DMF (2 mL) is added and the resulting reaction mixture is bubbled with air for 3 hours at room temperature. The reaction mixmre is partitioned between ether and water. The organic phase is washed with dilute hydrochloric acid, brine and dried over magnesium sulfate. After removal of solvent, die product is purified by silica gel chromatography. Example 275: Formula I: R= cyclopropylmethyl: R'= H: n= 1: Rl= H. Diazomethane (20 ml, 1 M in ether) is added dropwise into a solution of the product of Example 263 (0.2 g) and palladium (E) acetate (0.02 g) in ether (5 mL) at -5 °C. After stirring at -5 °C for 1 hour, the precipitate is filtered off and solvent removed in vacuo. The product is purified by silica gel chromatography. Example 276: Formular V: n= 1: Rl= H: R3i= H: R22= H: R22= OH: R24= H: R35. R3ά. R and R' taken together with the carbon atoms to which they are attached form a pyrrole with C- 22 and C-21 becoming positions 2' and 3' of the heterocyclic system. A solution of the product of Example 264 (0.5 g) in methylene chloride (10 mL) is tteated with ammonia (0.88 M, aq., 0.4 mL). After stirring at room temperamre for 0.25 hours, the reaction mixmre is partitioned between ethyl acetate and water. The organic phase is washed once with brine, dried over magnesium sulfate and solvent removed. The product is purified by silica gel chromatography. Example 277: Formular V: n= 1: Rl= H: R3i= H: R22= H: R2a= OH: R = H: R-3A Rao. R and R' taken together with the carbon atoms to which they are attached form a N-(beta- hydroxyethyD-pyrrole with C-22 and C-21 becoming positions 2' and 3' of the heterocyclic system. The title compound may be prepared from the product of Example 264 and 2-aminoethanol according to the procedure described in Example 276. Example 278: Formular V: n= 1: Rl= H: R21= H: R22= H: R22= OH: R34= H: Ra j . R . R and R r taken together with the carbon atoms to which they are attached form a N-benzylpyrrole with C-22 and C-21 becoming positions 2' and 3' of the heterocyclic system. The title compound may be prepared from die product of Example 264 and benzylamine according to the procedure described in Example 276. Example 279: Formular V: n= 1: Rl= H: R21= H: R22= H: R22= OH: R24= H: R-25. R . R and R r taken togedier with the carbon atoms to which they are attached form a N-phenylpyrrole with C-22 and C-21 becoming positions 2' and 3' of the heterocyclic system. The tide compound may be prepared from the product of Example 264 and aniline according to tine procedure described in Example 276. Example 280: Formular V: n= 1 : Rl= H: R3i= H: R22= H: R-3-2= OH: R = H: R3Λ Rao R and R' taken together with the carbon atoms to which they are attached form a N-methylpyrrole with C-22 and C-21 becoming positions 2' and 3' of die heterocyclic system. The tide compound may be prepared from the product of Example 264 and metiiylamine according to the procedure described in Example 276. Example 281 : Formular V: n= 1 : Rl= H: R3i= H: R2 = H: R22= OH: R = H: R . R-26. R and R' taken togedier witii the carbon atoms to which they are attached form a furan with C-22 and C-21 becoming positions 2' and 3' of the heterocyclic system. The product of Example 264 (0.2 g) and p-toluenesulphonic acid (0.005 g) in dry methylene chloride is refluxed under nitrogen for 1 hour. After removal of solvent die product is purified by sihca gel chromatography. Example 282: Formula IE: R= ethyl: R'= H: n= 1 : R3-l= H: R22= H: R22= ^-butyldimethylsilyloxy: R2 = H: R 3 ^- and R3£ taken together form an oxo group. A solution of the product of Example 54 (1.0 g) in acetonitrile (10 mL) was added into a stirred solution of HF (0.1 mL, 40% aqueous) in acetonitrile (10 mL) and stirred at room temperature for 10 min. Saturated sodium bicarbonate (0.5 mL, aqueous) was added and stirred for 20 min. Solvent was removed in vacuo. Etiier (50 mL) was added to die residue and the mixmre dried over magnesium sulfate. Sohd was removed by filtration and solvent removed in vacuo. The product was purified by sihca gel (20 g) eluting with 20% (v/v) acetone in hexanes. Yield: 0.67 g; MS (FAB) m/z: M+K = 944. - Ill - Example 283: Formula V: R= ethyl: R'= H: n= 1: R2= H: R2= H: R 3 - and R 4 - taken together form an oxo group: R21= H: R22= H: R22= t-butyldimethylsilyloxy: R-S4= H: R ^ ' and R3ά taken together form an oxo group. The tide compound was prepared from the product of Example 282 according to the procedure described in Example 48. MS (FAB) m/z: M+K = 942. Example 284: Formula V: R= ethyl: R'= H: n= 1 : R2= H: R21= H: R 3 - and R 4 - taken together form an oxime: Rll= H: R22= H: R = t-butyldimethylsilyloxy: R24= H: R& and R-26 taken together form an oxo group. N-methylmorpholine (0.1 mL) was added into a stirred solution of hydroxylamine hydrochloride (0.05 g) and the product of Example 283 (0.52 g) in absolute ethanol (3 mL) and stkred at room temperature for 1 hour. The reaction mixture was refluxed for 1 hour and solvent removed. The product was purified by sihca gel (20 g) eluting with 20% acetone in hexanes. Yield: 0.5 g; MS (FAB) m/z: M+K = 957. Example 314: Formula I: R= ethyl: R'= H: n= 1: Rl= benzenesulfonyloxy. Ascomycin (791 mg, 1 mmol) was dissolved in 6 mL of pyridine in an ice bath and benzenesulfonyl chloride (153.1 uL, 1.2 mmol) was added. It was tiien stirred at 0 °C for 15 min and at room temperature for 24 hours. Ethyl acetate (40 mL) was added to d e reaction mixture, and the organic layer was washed with brine, 10%-KHSθ4, brine and tiien dried over anhydrous magnesium sulfate. Evaporation of the solvent gave 961 mg of product MS (FAB) m/z: M+K=970. Example 315: Formula V: R= ethyl: R'= H: n= 1: Rl= N-phenylcarbamate: R21= H: R22= H: R3 = t-butyldimethylsilyloxy: R3 = H: R3-5 and take together form an oxo group. A solution of the product of Example 282 in THF is added to a solution of phenyl isocyanate in THF. It is then gentiy refluxed until die total disappearance of starting material is observed. Catalytic amount of TEA is used if neccesary. Solvent is removed, and is purified by silica gel column chromatography to yield the title compound. Example 316: Formula I: R= ethyl: R'= H: n= 1: Rl= N-phenylcarbamate. The product of Example 315 (200 mg) is dissolved in 2.5 mL of acetonitrile and 48% hydrofluoric acid (100 uL) is added. It is then stirred at room temperamre for 4 hours. Ethyl acetate (30 mL) is added to the reaction mixture, and the organic layer is washed witii brine, 10%-NaHCθ 3 , brine and then dried over anhydrous magnesium sulfate. Evaporation of the solvent gives crade product which is purified by sihca gel (25 g) column chromatography, eluting 1.5%-methanol in chloroform. Example 317: Formula I: R= ethyl: R f = H: n= 1: Rl= phenylthio. A solution of the product of Example 282 in methylene chloride is added to a solution of triflic anhydride in methylene chloride, according to the procedure described in Example la. To a solution of the obtained product in methylene chloride is added sodium phenylmercaptane in DMF. It is then gently warmed until die total disappearance of starting material is observed. Solvent is removed, and is purified by sihca gel column chromatography to yield die tide compound. C24-t-butyldimethylsilyl is removed according to die procedure described in Example 316 to give the title compound. Example 318: Formula I: R= ethyl: R'= H: n= 1: Rl= benzylthio. The title compound may be prepared from the product of Example 282 and sodium benzylmercaptide, according to the procedure described in Example 317. Example 319: Formula I: R= ethyl: R'= H: n= l: Rl=SH. The product of Example 318 is carefully added to anhydrous liquid ammonia. Sodium metal is added until the reaction is completed. Solvent is removed, die residue is dissolved in degassed water, and is purified by high performance liquid chromatography to yield the tide compound. Example 320: Formula I: R= ethyl: R r =H: n= 1: Rl= C2H SS-. The product of Example 319 is carefully dissolved in degassed water (or mixed solvent if necessary). Lithium thiocyanate hydrate and zinc chloride (E) are carefully added. After the total disappearance of starting material is observed, ethanethiol is added and stirred at room temperature for 5 hours. Solvent is removed, die residue is purified by sihca gel column chromatography to yield die title compound. Example 321: Formula E: R= H: R'=allyl: n= 1: taken together with die carbon atoms to which they are attached. R^. R2Z. R2S. and R-2S form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of the heterocyclic system: R-6Ω = OH (R configuration): R&= H. A solution of " 17-epi-FK-506" (as described in pubhshed European Patent Application No. 0356399) (0.41 g), o-phenylenediamine (0.108 g) and N-methylmorpholine (0.072 g) in absolute ethanol (3 mL) is refluxed under nittogen overnight. Solvent is removed in vacuo and product is purified on sihca gel (10 g) with metiiylene chloride/acetonitrile (5:2, v/v) elution, foUowed by 40% acetone in hexanes to give die desired compound. Example 322: Formula E: R= ethyl: R'=H: n= 1: taken togedier with the carbon atoms to which thev are attached. R-24 R-22. R2& n R2J. form a fused naphthalene group wherein the atoms adjacent to C-9 and C-10 are substituted by cyano groups: R6Ω = OH (7? configuration): R = H. Ascomycin (1 mmol) is reacted with 1,2-phenylenediacetonitrile and piperidine according to published methods of ring formation (Bull. Soc. Chim. Fr. 1946, 106; J. Am. Chem. Soc. 1951, 73, 436). Solvent is removed in vacuo and product is purified on silica gel to give the desired compound. Example 323: Formula E: R= ethyl: R'=H: n= 1: taken together with the carbon atoms to which thev are attached. R2ό and R 2 - 8 - are each OH: R-2Z and R 2 ^. taken together form -CH?- CrCH VCH - group : R≤Ω = OH (R configuration): Rά5= H. Ascomycin (1 mmol) is reacted with l-trimethylsilyl-2-iodomethyl-prop-2-ene and SnF according to published methods of ring formation (J. Am. Chem. Soc. 1986, 108, 4683). Solvent is removed in vacuo and product is purified on sihca gel to give the desired compound. Example 324: Formula V: R= ethyl: R'= H: n= 1: X= subformula la: Rl= TBSO- (R-configuration): Y= subformula IEa: R 3 -! and R 3 - 2 - taken together form diazo: R33- and R34 taken together form an oxo: R 3 -^ and R36 taken together form an oxo. The product of Example 8b (16.9 g, 18.7 mmol) in CH3CN containing water (0.34 mL, 18.7 mmol) and trietiiylamine (3.9 mL, 28.1 mmol, 1.5 eq) was tteated with a portion of methanesulfonylazide (4.5 mL, 56.2 mmol) at ambient temperature (7 hours). The mixture was concenttated in vacuo and filtered through a plug of sihca gel (300 mL, 70-230 mesh) eluting with hexane:EtOAc (IL, 2: 1). Fractions containing product were pooled and concenttated. This was purified further by HPLC on sihca gel (50mm x 500 mm, 230-400 mesh) eluting witii hexane:EtOAc (6L, 5:1). The appropriate fractions were combined and concenttated to provide product as a yellow foam (13.8 g, 14.8 mmol) in 79% yield. IR (CDCI3) 2130, 1743, 1645 cm " 1; MS (FAB) miz 968 (M+K), 940 (M+K-N2). Example 325: Formula V: R= ethyl: R'= R2$= R2&= H: n= 1: X=subformula la: Rl= TBSO- (R configuration): Y= subformula Ela': R 3 - 3 - and R^ 4 - taken together form an oxo. The product of Example 324 (13.8 g, 14.8 mmol) in N-methylpyrollidone (600 mL) containing water (96 mL) was heated at 110 °C for 80 min after gas evolution commenced. The mixture was cooled and partitioned between EtOAc (1 L) and water (1 L). The aqueous layer was exttacted with additional EtOAc (1 L). The organic layers were each washed sequentially with water (1 L) and brine (500 mL), and were tiien combined and dried (NaS04). The solvent was removed invacuo and the residue was passed through a silica gel column (300 mL, 70-230 esh) eluting witii a mixture of hexane:EtOAc (2: 1, 2 L). The fractions containing product were combined and concenttated to a yeUow oil (10 g) which was further purified by HPLC on sihca gel (IL, 230-400 mesh) eluting with hexane:EtOAc (5:1). This provided pure product (5.3 g, 6.1 mmol) in 41% yield. IR (CDCI3) 1750, 1722, 1705 (sh), 1645 cm ~l ; MS (FAB) miz 914 (M+K). Anal. Calcd. for C48H8INO11S1 C, 65.79; H, 9.32; N, 1.60. Found: C, 65.57; H, 9.08; N, 1.56. Example 326: Formula V: R= ethyl: R'= R^= R2!= H: n= 1: X= subformula lb: R 3 - and Re¬ taken together form an oxo: Y= subfoimula IEa: R 3 -! and R 3 - 2 - taken together form a diazo: R31 and R3 4 - taken togedier form an oxo: R 3 -^ and R 3 ^ taken together form an oxo. The product of Example 14a (3.56 g, 4.5 mmol) in acetonitrile (89 mL) containing water (82 micro-L, 4.5 mmol) and triethylamine (0.95 mL, 6.8 mmol, 1.5 eq.) was tteated with medianesulfonylazide (1.09 mL, 13.6 mmol, 3 eq.) for 6h. Volatiles were immediately removed invacuo and die residue purified by MPLC on 230-400 mesh Siθ2 (2.54 cm x 45 cm column) eluting with hexane:acetone (4:1) collecting 100 mL fractions throughout which provided pure product (2.73g, 3.35 mmol) in 75% yield. IR (film) 2930, 2115, 1725, 1645, 1455, 1200 cm ~ 1; MS (FAB) miz (M+K+thioglycerol)= 932, (M+K)= 852, (M+K-N2)= 824. Example 327: Formula V: R= ethyl: R r = R2= R2= H: n= 1 : X= subformula lb: Y= subformula Ela': R23- and R2 - taken together form an oxo. The product of Example 326 (1.0 g, 1.23 mmol) in N-methylpyrolhdone (50 mL) and water (8 mL) was heated at 110 °C (45 min). The reaction mixture was cooled and partitioned between water (500 mL) and EtOAc (300 mL). The aqueous layer was extracted witii additional EtOAc (300 mL). The organic layers were washed witii additional water (500 mL) and brine (500 mL), combined, and dried (Na2Sθ4). The extract was decanted from die drying agent and concenttated to a colorless foam (1.04 g), which was purified by sihca gel chromatography (70-230 mesh, 300 mL) eluting with hexane:acetone (4:1, 2.5 L). The appropriate fractions were pooled and concenttated to provide pure product (0.55 g, 0.72 mmol) in 59% yield. IR (CDCI3) 1743, 1721, 1643 cm -1; MS (FAB) miz 798 (M+K). Anal. Calcd. for C42H65NO11: C, 66.38; H, 8.62; N, 1.84. Found: C, 66.74; H, 8.29; N, 2.25. Example 328: Formula V: R= ethyl: R'= R = R35= R^ H: n= 1: X= subformula la: RJ= TBSO- (R configuration'): Y= subformula IEa': R-22= OH. A 1.0M solution of LiAlH(Ot- ^ .a)3 in THF (8.2 mL, 8.2 mmol) was added dropwise to the product of Example 325 (1.8 g, 2.05 mmol) in THF (8.0 mL) at -78 °C and allowed to stir for lh, whereupon it was warmed to -40 °C and stirred at this temperamre for 24h. The reaction was quenched by the addition of acetone (1.1 mL) and then stirred vigorously at room temperature for 15 minutes with a saturated aqueous solution of sodium potassium tartrate (30 mL). The mixmre was partitioned between water (60 mL) and EtOAc (100 mL). The organic layer was washed witii IN HCl (40 mL) and brine (2 x 50 mL). Ah aqueous layers were exttacted with additional EtOAc (100 mL). The organics were combined, dried (Na2S04) and concenttated in vacuo. Purification by chromatography on 70-230 mesh silica gel (20 g) eluting with toluene:EtOAc (5:1) provided pure product (0.9 g, 1.03 mmol) as a colorless foam in 50% yield. IR (CDCI3) 1735, 1720 (sh), 1670, 1645 cm - 1 ; MS (FAB) miz 918 (M+K). Example 329: Formula El: R= ethyl: R'= R2A= R35^ R3 = H: n= 1: Y= subformula IEa': R33= QH. A IM solution of HF (0.35 mL, 0.35 mmol (0.42 mL 48% aqueous HF in 9.58 mL CH3CN provides a IM solution)) was added dropwise to a solution of the product of Example 328 (290 mg, 0.33 mmol) in acetonitrile (3.2 mL) at 0 °C. The mixmre was warmed to room temperature and stirred for 45 minutes, whereupon it was cooled to 0 °C and sohd pulverized NaHCθ3 (244 mg, 2.9 mmol) was added. After 30 minutes anhydrous MgS04 (250 mg) was added and the mixture stirred for 15 minutes, when it was diluted with methylene chloride (15 mL), centrifuged and passed thru a plug of silica gel. The silica was eluted witii hexane:acetone (1:1), and the fractions containing product were pooled, concenttated and purified by HPLC on sihca gel eluting with hexane:acetone (2:1) providing desired product (163 mg, 0.21 mmol) in 64% yield. IR (CDCI3) 1735, 1645 cm - 1 ; MS (FAB) miz 802 (M+K). Anal. Calcd. for C42H69NO11: C, 66.03; H, 9.10; N, 1.83. Found: C, 65.92; H, 8.93; N, 1.76. Example 330: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH2C(O)OCH2(9-fluorenyl) CR configuration). Ascomycin (10 g, .012 mol) was dissolved in distilled CH2CI2 (50 ml). Rhodium (E) acetate dimer (100 mg) was added and die mixmre cooled to 0 °C. 9-Ruorenylmethyl diazoacetate (3.35 g, .012 mol) was dissolved in CH2CI2 (10 mL) and the solution added to die reaction via syringe pump at a rate of approximately 0.5 mL/hour. Addition was complete in approximately 24 hours. The reaction was stirred at 0 °C for an additional 24 hours tiien loaded onto sihca (230-400 mesh, 400 g) and die solvent evaporated by airflow in the hood. The adsorbed sihca was layered over fresh sihca (800 g) in a 1 L fritted glass funnel. The sihca plug was eluted with the following solvents: CH2CI2 (2 L), 3:1 CH2CI2/CH3CN (4 L), 2:1 CH2CI2 CH3CN (3 L), and 1:1 CH2CI2/CH3CN (3 L). Fractions containing product were combined and concenttated in vacuo to give 7.32 g yellow foam. Fractions containing ascomycin were combined and concentrated in vacuo to give 3.30 g green foam (contains some catalyst). The product was further purified by HPLC (silica gel, 230-400 mesh, 50 x 500 mm column) eluting with 3.5:1 hexane/acetone at a flow rate of 80 rnl/min. Fractions containg purest material were combined and concenttated in vacuo to give the title compound as a white foam (4.0 g, 45% yield based on recovered ascomycin). IR (KBr) 3440, 1740, 1710 (sh), 1650 cm"l; MS (FAB) miz 1066 (M+K). Anal, calcd. for C59H8INO14O H2O C, 68.08; H, 7.98; N, 1.35. Found: C, 68.11; H, 7.88; N, 1.51. Example 331: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH9C(O10H CR configuration'). The resultant product of Example 330 (5.10 g, 5 mmol) was dissolved in CH2CI2 (45 mL) then piperidine (5 ml) was added. The solution was stirred at room temperamre for 2 hours then ttansferred to a separatory funnel, diluted with addtional CH2CI2 (100 mL), then washed with IN HCl (2 x 100 mL) and brine (2 x 100 mL). The organic layer was dried (Na2Sθ4), filtered, and the solvent removed in vacuo to give 5.08 g of a mixture of the title compound and 9-methylenylfluorene. MS (FAB) miz 888 (M+K), 926 (M+2K-H). Example 332: Formula I: R= ethyl: R'= RJ ^ H: n= 1: RJ= -COftCfC R^ RJ2= NRHR15 : I^ -CH9CH9CriHs. The product of Example 331 (100 mg, .118 mmol) was dissolved in dichloromethane (1 mL) and the solution cooled to 0 °C. HOBTΗ2O (21.6 mg, .142 mmol) was added followed by EDAC (27.1 mg, .142 mmol) tiien phenethylamine (26.7 μL, .212 mmol). The reaction was warmed to room temperature and sthred overnight Dichloromethane (10 mL) was added and die organic phase washed witii IN HCl (2 x 20 mL), saturated bicarbonate solution (2 x 20 mL), and tiien brine (2 x 20 mL). The organic layer was dried (Na2Sθ4), filtered, and solvent removed in vacuo to give 87.5 mg yellow foam. The crude product was purified by HPLC (20 x 300 mm silica column) eluting with 2:1 hexane/acetone. Fractions containing product were combined and solvent removed in vacuo to give the tiύe compound (49.6 mg, 44% yield) as a white sohd: 93-105 °C (mp); IR (KBr) 3435, 1740, 1700, 1650 cm" 1 ; MS (FAB) miz 953 (M+H), 991 (M+K). Anal, calcd. for C53H8ON2O13: C, 66.78; H, 8.46; N, 2.94. Found: C, 67.13; H, 8.33; N, 3.04. Example 333: Formula I: R= ethyl: R'= H: n= 1: Rl= -OC CfO l 2 -; R!2= NRHRI 5 -: RI^ CH^: R^= -CH9CH9C6HS. Example 332 was repeated substimting N,N-methyl, 2-phenylethyl amine for 2-phenylethylamine to provide the tide compound. Example 334: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH9Crθ)Rl2 : RJ2= The title compound was synthesized in die manner described for Example 332 substituting dansyl cadaverine for 2-phenylethylamine. IR (KBr) 3420, 1740, 1700, 1645 cm" 1 ; MS (FAB) miz 1205 (M+K). Anal, calcd. for C62H94N4O15S: C, 63.78; H, 8.12; N, 4.80. Found: C, 63.43; H, 8.25; N, 4.48. The title compound was synthesized in the manner described for Example 332 substimting aniline for 2-phenylethylamine. 112-120 °C (mp); IR (KBr) 3440, 3400 (sh), 3300 (sh), 1740, 1700, 1650, 1540, 1500 cm "1 ; MS (FAB) miz 963 (M+K). Anal, calcd. for C51H76N2O13: C, 66.21; H, 8.28; N, 3.03. Found: C, 66.11; H, 8.15; N, 3.23. The title compound is synthesized in the manner described for Example 332 substimting 2-(4- morpholino)-ethylamine for 2-phenylethylamine. The tide compound is syntiiesized in the manner described for Example 332 substimting 3-(4- moi holmo)-propylamine for 2-phenylethylamine. The title compound is synthesized in die manner described for Example 332 substimting 2-dimethylamino-ethylamine for 2-phenylethylamine. The title compound is synthesized in die manner described for Example 332 substimting 3-dimethylanjino-propylamine for 2-phenylethylamine. Example 340: Formula I: R= ethyl: R'= H: n= 1 : Rl= -(XΗ^CCOim R! = The tide compound was synthesized in die manner described for Example 332 substimting L-phenylalanine benzylester for 2-phenylethyIamine. MS (FAB) miz 1125 (M+K). Example 341: Formula I: R= ethyl: R'= H: n= 1: RJ= -OCH9Crθ)Rl2 : Rl2= The tide compound was synthesized in d e manner described in Example 111 substituting the product from Example 340 for the product from Example 110. IR (CDCI3) 1740, 1700(sh), 1645 cm- 1 ; MS (FAB) miz 1035 (M+K). Example 342: Formula I: R= ethyl: R'= H: n= 1: RJ= -OC crOIR-l 2 -: RJ2= (U)-HNCH(CH9CfflΛ)C09CH9Ph. The title compound is syntiiesized in the manner described for Example 332 substimting D-phenylalanine benzylester for 2-phenylethylamine. Example 343: Formula I: R= ethyl: R'= H: n= 1: Rl= -OO CfOIRl 2 -; R12= rR)-HNCHfCH9CfiH )CQ9H. The title compound is syntiiesized in die manner described in Example 111 substimting the product from Example 342 for the product from Example 110. Example 344: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH9CfO')Rl 2 -: RJ2= -HN(CH9^9SH. The title compound is synthesized in the manner described for Example 332 substimting 2-amino-ethanethiol for 2-phenylethylamine. Example 345: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH Crθ')Rl2: RI2= The title compound is syntiiesized in die manner described for Example 332 substimting 3-amino-propanethiol for 2-phenyIethylamine. Example 346: Formula I: R= ethyl: R'= H: n= 1: Rl= -OCH2CfO')OC9H<; CR configuration'). Silver (I) oxide (926 mg, 4.0 mmol) was added to ascomycin (791 mg, 1.0 mmol) dissolved in acetonitrile (0.8 mL) and ethyl iodoacetate (828 μL, 7.0 mmol). Mixmre was stirred at room temperamre for 3 days, removed volatiles in vacuo, and isolated product by chromatography on silica gel as described in Example 109. Spectral data were identical to those obtained for the product of Example 109. Example 347: Formula I: R= ethyl: R'= H: n= 1: R-l= -OC(O ormo-Wθ2)-CfiHA 01 configuration-). Ascomycin (791 mg, 1.0 mmol) and trietiiylamine (0.28 mL, 2.0 mmol) in dichloromethane (10 mL) were cooled to 0 °C. 2-Nittobenzoylchloride (322 μL, 2.2 mmol) was added followed by DMAP (122 mg, 1.0 mmol). Warmed the mixmre to room temperamre and after 24 hours pardoned the solution between IN H3PO4 (30 mL) and EtOAc (30 mL). The aqueous layer was exttacted again with EtOAc (30 mL). The organics were washed with brine (2 x 30 mL), combined, dried (Na2Sθ4) and concenttated in vacuo. The residue was purified by HPLC on sihca gel eluting with hexane:acetone (2.5: 1) providing the title compound in 40% yield. MS (FAB) miz 979 (M+K). Example 348: Formula V: subformula IEa: R= ethyl: R'= R21= R22= R24= Hi n= 1 : Rl= -OC(0)-(ortho-Nθ2)-CtfΪA (R configuration'): R23= -OaO ortho-NO YCaϊA: R^= R 6= £ Also isolated from the products of Example 347 was die title compound. MS (FAB) miz 1128 (M+K). Example 349: Formula I: R= ethyl: R'= H: n= 1: R-l= -OC(0)-2-pyridyl CR configuration'). l-(3-Dimemylaminopropyl)-3-edιylcarbodiimide hydrochloride (700 mg, 3.7 mmol) was added at 0 °C to ascomycin (791 mg, 1.0 mmol), picolinic acid (381 mg, 3.1 mmol) and triethylamine (0.28 mL, 2.0 mmol) in dichloromethane (10 mL) followed by DMAP (122 mg, 1.0 mmol). The mixture was warmed to room temperature and stirred for 36 hours, whereupon it was partitioned between EtOAc (30 mL) and water (30 mL). Organics washed with brine (2 x 30 mL). Aqueous portions reextracted with EtOAc (30 mL), organics were combined, dried (Na2Sθ4) and concenttated in vacuo. Residue was purified by HPLC on silica gel eluting with hexane: acetone (1: 1) to provide die title compound. MS (FAB) miz 935 (M+K). Example 350: Formula V: subformula IEa: R= ethyl: R'= R3J-= R34= = H: n= 1 : Rl= -OCrθ)-2-ρyridyl (R configuration'): R32 and R23 taken together form a bond: R3-5= R3i.= Q. Also isolated from the products of Example 349 was the title compound. MS (FAB) miz 917 (M+K). Example 351: Formula V: subformula IEa: R= ethyl: R'= R2 = R22= 3 ^ H: n= 1 : RJ= -OCrθV2-pyridyl CR configuration'): R^ = -OC(OV2-pyridyl: R3 = R36= Q. Also isolated from the products of Example 349 was the tide compound. MS (FAB) miz 1040 (M+K). configuration). The title compound is synthesized in die manner described in Example 111 substimting the product from Example 347 for the product from Example 110. Example 353: Formula V: subformula IEa: R= ethyl: R'= R3-1= R22= R34= H: n= 1: R!= R3-6= Q. The title compound is syntiiesized in the manner described in Example 111 substimting the product from Example 348 for the product from Example 110. Example 354: Formula El: R = ethyl: R' = H: n = 1: R2 = R1 = H: one of R23- and R2 4 = H and die other = N-benzylpiperazinyl: R 3 -^ and R taken together form oxo. The product of Example 36 (500 mg, 0.65 mmol) was dissolved in 5 mL of methylene chloride containing 1-beπzyl-piperazine (337 μL, 1.95 mmol) and trietiiylamine (270 μL, 1.95 mmol). The mixmre was stirred at room temperature for one over night Ethyl acetate (50 mL) and brine solution were added and partitioned. The ethyl acetate layer was washed witii brine (x3), dried over anhydrous magnesium sulfate. Purification was carried out by sihca gel column, foUowed by HPLC to obtain the tide compound. Yield 159 mg (26%), MS (FAB) miz: M+H = 950, M+K = 988. Example 355: Formula El: R = ethyl: R' = H: n = 1: R3 = R-22 = H: one of R23- and R = H and die otiier = N-methylpiperazinyl: R 3 -^ and R3≤ taken together form oxo. The title compound was prepared from the product of Example 36 (700 mg, 0.91 mmol) and 1-metiιylpiperazine (507 μL, 4.55 mmol), according to the procedure described in Example 354. Yield 208 mg (26%), MS (FAB) miz: M+H = 874, M+K = 912. Example 356: Formula El: R = ethyl: R' = H: n = 1: Rug R22 = H: one of R33- and R = H and the other = N-phenylpiperazinyl: R 3 -^ and R2ό taken together form oxo. The title compound was prepared from the product of Example 36 (500 mg, 0.65 mmol) and 1-phenylpiperazine (493 μL, 3.25 mmol), according to the procedure described in Example 354. Yield 248 mg (41%), MS (FAB) m/z M+H = 936, M+K = 974. Example 357: Formula I: R= ethyl: R'= H: n= 1: Rl= azido (R Configuration). To a stirred solution of die product of Example 9 (0.9 g, 1 mmol) in methylene chloride (2 mL) was added n-tettabutylammonium azide (3.5 mmol) in chloroform (10 mL). After stirring at 45°C ovemight and at room temperamre for 3 days, the reaction mixmre was treated according to the procedure described in Example lb and was further purified by HPLC (high performance liquid chromatography) to obtain the title compound (66.2 mg). miz: M+K = 855; IR(KBr) 3490-3420, 2960, 2940, 2875, 2820, 2100, 1740, 1720, 1705, 1650, 1455, 1380, 1350, 1285, 1245, 1200cm" 1 . Example 358: Formula VE: R= ethyl: R'= H: n= 1: Rl= azido fS Configuration'): R21 and R-22 taken together form an oxo group: R 3 -! and R33- taken together form a bond: 32= H: R34= H: R35 and R-26 taken together form an oxo group. The tide compound was isolated as a by-product from the reaction described in Example lb. Yield: 53.0 mg. MS (FAB) miz: M+K = 837; IR(KBr) 3430, 2960, 2930, 2870, 2825, 2090, 1735, 1715, 1670, 1650, 1625, 1590, 1450, 1375, 1360, 1345, 1325, 1280, 1270, 1250, 1235, 1200cm- 1 . Example 359: Foimula I: R= ethyl: R'= H: n= 1: Rl= IC^CfO'tNH fS-Configuration'). The product of Example 2 (316.4 mg, 0.4 mmol) in 5 mL of methylene chloride at 0°C was tteated with iodoacetic anhydride (169.9 mg, 0.48 mmol), triethylamine (0.115 mL, 0.8 mmol) and DMAP (4 mg, 0.04 mmol), and die mixture was stirred at 0 C for 2 hours and at room temperamre for 6 hours. Ethyl acetate (25 mL) was added, and die organic layer washed witii 10%-KHSO4, brine, 10%-NaHCθ3, brine, and then dried over magnesium sulfate. The crade product (383.6 mg) obtained was purified by HPLC. Yield: 37.1 mg; MS (FAB) miz: M+K = 997. Example 360: Formula I: R= ethyl: R'= H: n= 1: R = Diethylphosphoryloxy (R-Configuration). Ascomycin (474 mg, 0.6 mmol) was dissolved in 8 mL of benzene at 0 °C. Triethylamine (250 μL, 1.8 mmol), diethylchlorophosphate (250 μL, 1.8 mmol), followed by DMAP (15 mg, 0.12 mmol) were added to the reaction mixture. It was stirred at 0 °C for 15 minutes and allowed to warm to room temperature. After stirring overnight, 20 mL of cold 10%-NaHSθ 4 aqueous solution was carefully added to the cooled reaction mixture. Ethyl acetate (40 mL) was added to exttact the compound. The organic layer was washed witii 10%-NaHSθ4, brine, saturated NaHCθ 3 , brine and dried over anhydrous magnesium sulfate. After the solvent was removed, 632 mg of crude product was obtained. This was purified by reverse phase-HPLC to yield 140 mg of pure tide compound in 25 % yield. MS (FAB) miz: M+K = 966. Example 361: Formula IV: R= ethyl: R'= H: n= 1: R1= H. R 2 1=0H. R22=H. The product of Example 11 (3.24 g, 3.5 mmol) was dissolved in 40 mL of benzene under nittogen atmosphere. AIBN (2,2'-azobis[2-methylpropanenitrile], 29 mg) and tributyltin hydride (1.4 mL, 5.25 mmol) was added to die reaction mixture. The mixture was gently refluxed at 80 °C for 4 hours, and solvent was removed. The residue was dissolved in etiiyl acetate (60 mL) and washed with brine (30 mL x 2), 10% sodium bisulfate (30 mL x 3), brine (30 mL x 1) , saturated sodium bicarbonate (30 mL x 3), and brine (30 mL x 3). It was then dried over anhydrous magnesium sulfate. Purification of die crude product (5.01 g) was carried out by sihca gel column, fohowed by reverse phase HPLC to obtain the title compound. Yield 466 mg (17%), MS (FAB) miz: M+K = 816. Example 362: Formula I: R= ethyl: R'= H: n= 1: R2=H. R !. R21 and R- 4 - taken together form a bond). C-32-Trifluoromethanesulfonyl-C-24-rertbudydimedιylsilyl ascomycin (580 mg, 0.16 mmol) was dissolved in 4 mL of methylene chloride and triethylamine (684 μl, 1.68 mmol) was added. The mixmre was stirred at 50°C for 3 hours and at room temperature overnight. Methylene chloride was evaporated and ethyl acetate (40 mL) added to die residue, which was washed witii 10% sodium hydrogen sulfate (20 mL 3), brine (20 mL), saturated sodium bicarbonate (20 mL x 3) and brine (20 mL x 3), and dried over magnesium sulfate. After deprotection according to die procedure of Example 60, the tide compound was obtained by sihca gel chromatography, followed by normal phase HPLC. Yield: 50 mg (12%); MS (FAB) miz: M+K = 812. Example 363: Formula V: R= ethyl: n=l: R'= H: R-l= r-butyldimethylsilyloxy: R.31= H: R22= H: RS2= OH: R =H: R2≤= -O-benzoyl fS-configuration'): R26= H. To a stirred solution of 32-TBDMS, 22-S-dihydro ascomycin (prepared according to die procedure of Example 103c, 0.14g, 0.15 mmol) and triethylamine (0.10 mL, 0.75 mmol) in CH 2 C1 2 (3 mL) was added benzoyl chloride (0.052 mL, 0.45 mmol) followed by DMAP (0.002g, 0.015 mmol). The reaction was stirred at room temperature overnight and then diluted witii ethyl acetate. The ethyl acetate layer was washed with 0. IM H3PO4, NaHCθ3, brine and dried over Na 2 S04. Evaporation provided the title compound (0.13g). Example 365: Formula III: R= ethyl: n=l: R'= H: Rϋ= H: R22= H: R22= OH: R34= H: R25= -O-benzoyl (S-configuration): R3≤= H. The crade product derived from the procedure of Example 363 (0.13g) was tteated with HF according to the procedure of Example 60 and then purifiedby RP-HPLC (41.4 mm ID, Dynamax-60A 8μm phenyl, 83-D41-C) to give 0.085g of the title compound in 64% yield. FAB-MS (m/z) 936 (M+K). Examples 365a and 365b: Formula V: R= 2-hydroxyethyl: n= 1: R'= H: Rl= tt-butyldimethylsilyloxy: R3-l= H: R22= H: R22= t-butyldimethylsilyloxy: R = H: R25 and R36 taken together form an oxo group, and Formula VE: R= 2-hydroxyethyl: n=l: R'= H: Rl= t-butyldimethyl-silyloxy: one of R 1 and R22 is H and the other is OH: R23= OH: R24= R21= H: R22= H: R23-= t-butyldimethylsilyloxy: R24= H: R 3 -^ and R 3 -^ taken together form an oxo group. To a stirred solution of 32,24 -bisTBDMS , 21-ethanal ascomycin (0.50g, 0.50 mmol, prepared according to the methods described in pubhshed PCT applications Nos. WO 89/05304 and WO 91/04025) and sodium triacetoxyborohydride (0.3 lg, 1.45 mmol) in CH3CN (15 mL) at 0°C was added acetic acid (0.25 mL, 4.36 mmol). The reaction mixture was stirred at 0° for 2 hours, quenched with water, and stirred for another 0.5 hour while warming to room temperature. The reaction mixmre was then partitioned between ethyl acetate and brine. The ethyl acetate layer was washed sequentially witii aqueous NaHCθ3 and brine, dried over Na S04 and concentrated to give 0.56g of crade product. Purification was done by sihca gel column chromatography, eluting with 7.5% to 15% acetone in hexane. The desired product 32,24-bisTBDMS, 21-ethanol ascomycin (Example 365a, 0.1 lg) was collected along with die starting material (0.13g) and the direduction product (Example 365b, 0.06g) which was also reduced at position C-9. Example 366: Formula V: R= 2-benzoyloxyethyl: n= 1: R'= H: Rl= t-butyldimethylsilyloxy: Rll= H: R3 = H: R23-= t-butyldimethylsilyloxy: R- = H: R25 and R2ά taken together form an oxo group. The product of Example 365a (32,24-bisTBDMS, 21-ethanol ascomycin, HOmg) was reacted with benzoyl chloride using the same conditions used in Example 363. Purification of the titied bis-TBDMS protected benzoate was achieved using a sihca gel column. Yield: 90mg. Example 367: Formula El: R= 2-benzoyloxyethyl: n=l: R'= H: R-3i= H: R = H: R22= OH: R2-4= H: R-25 and R3-6 taken together form an oxo group. The product of Example 366 (32,24-bisTBDMS, 21-etiιyl benzoate ascomycin, 90mg) was tteated witii HF according to die procedure of Example 60 and purified by RP-HPLC to give 0.04g of the title compound. FAB-MS (m/z) 950 (M+K). Anal.Calcd. for C 5 oH 73 NιOi4 » H 2 0 : C, 64.57; H, 8.13; N, 1.51. Found : C, 64.66; H, 8.02; N, 1.71. Examples 368a and 368b: Formula IE: R= ethyl: n= 1: R'= H: R21= H: R22= H: R = H: R23- and R- 3 -S-CS-configuration') taken together form -O-CfCHVb-O-: ^= H. and Formula IE: R= ethyl: n= 1: R'= H: R = H: R22= H: R^= H: RSI and R2 fR-configuration) taken together form - Q -CfCH b-O-: R36=H. To a stirred solution of ascomycin (0.5g, 0.6 mmol) in CH3CN (8 mL) at 0°C was added acetic acid (0.12 mL, 2.1 mmol) fohowed by sodium triacetoxyborohydride (0.15g, 0.7 mmol). The reaction was stirred at 0°C for 2 hours and quenched witii water. The ice bath was removed and die reaction mixture was stirred for another 0.5 hour while warming to room temperature. The reaction mixture was partitioned between ethyl acetate and brine. The organic layer was washed sequentially witii aqueous NaHC03 and brine, and dried over Na 2 S04. The solvent was concentrated to give 0.5 lg of crude material containing both S and R isomers of C22-dihydro ascomycin along with the unreacted starting material. The above crade material was dissolved in DMF (5 mL) containing dimethoxypropane (5 mL). Pyridinium p-toluenesulfonate (0.05g) was added, and die mixture was stirred at die room temperamre overnight. The reaction mixture was diluted witii etiier and washed witii brine. The ether was dried over Na 2 Sθ4 and evaporated to give 0.56g of d e crade C22,24- acetonides. Purification was done by RP-HPLC (41.4 mm ID, Dynamax-60A 8um phenyl, 83-D41-C) to isolate 0.15g of C22-S,24-acetonide and 0.025g of C22-R,24-acetonide isomer along with 0.096g of ascomycin and 0.03g of C22-R-dihydro ascomycin. 1H-NMR d 1.3 (s, 6H) for 22,24-S-acetonide , d 1.42 (s, 6H) for 22,24-R-acetonide; FAB- MS (m/z) 872 (M+K) Example 369: Formula V: R= ethyl: n= 1: R'= H: Rl= t-butyldimethylshyloxy: R3-l= H: R22= H: R22= OH: R = H: R25= -O-O^Bn (S-configuration): R&= H. 32-TBDMS, 22-S-dihydro ascomycin (0.5g,0.63mmol), prepared according to the procedure of Example 103c, N-φenzyloxycarbonyloxy)succinimide (0.27 ' g, 1.1 mmol) and DMAP (0.07g, 0.63 mmol) in CH 2 C1 2 (10 mL) were stirred at room temperature for 7 days. Purification was done by sihca gel column chromatography, eluting with 5/95 acetone/hexane to give 0.3 lg of 32-TBDMS, 22-S-benzyl carbonate ascomycin in 54% yield. Example 370: Formula IE: R= ethyl: n= 1: R'= H: R = H: R22= H: R22= OH: R24= H: R25= -Q-Cθ2Bn re-configuration): R26= H. The product of Example 369 is tteated with HF according to the procedure of Example 60 and purified by RP-HPLC to give the title compound. Example 371: Formula VI: R = ethyl: R' = H: n = 1: R-26. R22 and the carbon to which thev are attached are absent: one of R-2& and R- 2 ^ is hydroxy and the other is -COOC r. C-8 is directiv attached to C-10: R31= H: R22= H: R22= H: R34= H: R 3 ^ and R-36 taken together form an oxo group: R-6Q = hydroxy (R configuration): R&= H. To a stirred solution of 24-desoxy ascomycin, the product of Example 380 (0.155g, 0.2 mmol) in 1 mL of methanohc ErCl3-6H 2 0 (0.2 M) was added trimethylorthoformate (0.15 mL, 1.4 mmol). After stirring at room temperature for 5 hours, the reaction mixture was poured into aqueous NaHCθ3 and exttacted witii ether. The ether layer was washed witii brine, dried over Na 2 S04, and evaporated to give the crade product. After purification by RP-HPLC, the title compound (0.1 lg) was isolated in 69% yield. FAB-MS (m/z) 846 (M+K) Examples 372a and 372b: Formula E: R = ethyl: R' = H: n = 1 : R2&. R22 and the carbon to which they are attached are absent: one of R-2& and R22 is hydroxy and the other is -COOCHr C-8 is direcdy attached to C-10: RάΩ = hydroxy (R configuration ' ): R&= H. and Formula VI: R = ethyl: R' = H: n = 1: R26. R22 and the carbon to which thev are attached are absent: one of R2& and R 2 ^ is hydroxy and the other is -COOCHr C-8 is directiv attached to C-10: R-3-1 and R2- taken together form a bond: 22= H: RH= H: R = OCH R&= OCHr Rfll = hvdroxy (R confi uration'): Rό5= H. The procedure of Example 371, in which 24-desoxy ascomycin was replaced witii ascomycin, produced the tide compounds of Examples 372a and 372b as major and minor products FAB-MS (m/z) 890 (M+K). Example 373: Formula El: R = ethyl: R' = H: n = 1 : R 3 ! = R 3 ^ = R = H: R^ 3 = hvdroxy: R or R36 = H and the other -NR2& where R 3 ^ = -NHSfObR^ and R 4 ^ = 4-methylphenyl. The hydrazone obtained in Example 221 (1.00 g, 1.04 mmol), sodium cyanoborohydride (261 mg, 4.16 mmol) and /7-toluenesulfonic acid monohydrate were combined in a mixture of N,N-dimethylformamide and sulfolane (1:1, 46 mL). This mixmre was heated at 110 °C for 5.5 hours under a nittogen atmosphere. The reaction mixmre was diluted with water (200 mL) and exttacted witii ether (200 mL). Several washings of the organic phase were required to remove N,N-dimedιylformamide and sulfolane. The ether layer was dried over sodium sulfate, and die solvent was removed under reduced pressure. The crude material was purified by flash chromatography on sihca gel eluting witii 40% acetone in hexane. The title compound was obtained as a sohd (176 mg): mp 84-87 °C; IR (CDCI 3 ) cm- 1 3430, 2940, 1735, 1630, 1455, 1170, 1090; MS (FAB) mle: M+K = 1000. Example 374: Formula El: R= ethyl: R'= H: n= 1 : R3-l= H: R22= H: R-22= OH: R&= H: one of R25 or R26 = -NH2 and the other is H. The oximes obtained from Example 7 (50 mg, 0.062 mmol) were combined with 10% palladium on charcoal in ethanol (10 mL, 100%). The mixture was placed under a hydrogen atmosphere (1 atm) and stirred at ambient temperature overnight. The catalyst was removed by passing the mixture through a filter agent and the filtrate was evaporated to dryness to provide the title compound in quanititative yield: MS (FAB) mie: M+K = 831. Example 375: Formula V: R= ethyl: R r = H: n= 1 : Rl= H: R-^ R22= R32= R-2 4 = H: R 3 ^ and RS * taken together form an oxo group. The product of Example 259 is dehydrated as described in Example 36. This material is subsequendy hydrogenated as described in Example 380 below to furnish the title compound after purification by flash chromatography on sihca gel eluting with acetone and hexane. Example 376: Formula V: R= ethyl: R'= H: n= 1 : R2= R2= H: R4 and R21 taken together form a bond: R3-l= R32= R3-3-= R = H: R3-5 and R3& taken together form an oxo group. The product of Example 380 is dehydrated according to the procedure described in Example 362. Example 377: Formula V: R= ethyl: R'= H: n= 1 : R = Rl = R2I = H: R4= OH. R3i= R2 = R22= R = H: R 3 -^ and R3-& taken together form an oxo group. The product of Example 51 is dehydrated as described in Example 36. This material is subsequendy hydrogenated as described in Example 380 below to furnish the title compound after purification by flash chromatography on silica gel eluting with acetone and hexane. Example 378: Formula VI: R= ethyl: R'= H: n= 1 : taken together with the carbon atoms to which they are attached. R2£. R^I. R 2 ^- and R22 form a quinoxaline with C-9 and C-10 becoming positions 2' and 3' of die heterocyclic system: R 3 -! = R22 = R3 = R = H: R 3 -^ and R3-6 taken togedier form an oxo group: R6 = OH (R configuration): R-65= H. The product of Example 38 is hydrogenated as described in Example 380 to supply the tide compound after purification by flash chromatography on sihca gel eluting with acetone and hexane. Example 379: Formula V: R= ethyl: R'= H: n= 1: Rl= -OCH2CfO')OC2Hs fR-configurationV. R-3-l= R32= R 3 - 3 ^ R24= H: R 3 -^ and R 3 -^ taken together form an oxo group. The product of Example 109 is dehydrated according to the procedure described in Example 36. This material is combined with 10% palladium on carbon in ethanol and reduced under a hydrogen (1 atm) environment over 2 hours. The catalyst is removed using a filter agent and die filtrate is concenttated under reduced pressure. The crude material is purified by flash chromatography on sihca gel eluting with acetone in hexane. Example 380: Formula El: R= ethyl: R'= H: n= 1: R 3 - 1 =R2 2 =R 3 =R 4 =H: R ^ and R taken together form an oxo group. The enone obtained in Example 36 (1.00 g, 1.29 mmol) was combined with 10% palladium on carbon (100 mg) in methanol and reduced under a hydrogen (1 atm) environment for 4 hours. The catalyst is removed by passing the mixmre through a filter agent and the filtrate is concenttated under reduced pressure. The crade material was purified by flash chromatography on silica gel eluting with 25% acetone in hexane to supply the title compound (348 mg) as a colorless foam: MS (FAB) le: M+K = 814. Examples 381a and 381 h: Formula IE: R= ethyl: R'= H: n= 1: R&= H: R = -Q-: R&= R3 = H: R3-5 and R2ά taken together form =N- which is attached to the -O-at R-3 - to form an isoxazoline. and Formula III: R= ethyl: R'= H: n= 1: R22= -Q-: R3 = H: Rϋ= R32= H: R& and R-36 taken together form =N- which is attached to die -O- at R-23- to form an isoxazoline The oxime mixmre obtained in Example 7 (250 mg, 0.310 mmol) was dissolved in methylene chloride (25 mL), and the solution was chilled to 0 °C. Martin sulfurane dehyrating reagent (208 mg, 0.310 mmol) was added. Two more equivalents of dehydrating reagent were added after one and two hours of reaction respectively. The reaction was quenched witii isopropanol (3 mL), and die mixture washed witii saturated aqueous bicarbonate solution (80 mL). The organic phase was dried and freed of solvent The products were separated and purified by flash chromatography on silica gel eluting with 30% acetone in hexane. Example 381a: MS (FAB) mle: M+K = 827. Example 381b: MS (FAB) mle: M+K = 827. Example 382: Formula El: R= ethyl: R'= H: n= 1: R21 =R32= R34= H: R33. = QH: R and R-36 taken together are =NR4& where R4& is -OCH2CH=CH2_ ' Ascomycin (2.02 g, 2.54 mmol) was dissolved in 90% ethanol (40mL) To this solution was added O-allyl hydroxylamine hydrochloride (0.6275 g, 5.72 mmol) followed by pyridine (0.2mL, 2.54 mmol). The reaction was stiπed at room temperamre for 23 hours. It was then poured into water (75 mL) and exttacted witii ethyl acetate (2 x 75mL). The extracts were combined and washed witii brine (50 mL) and dried over magnesium sulfate. Removal of the solvent gave crude material which was flash chromatographed on sihca gel eluting witii 30% acetone in hexane. Yield 1.97g: MS (FAB) mle: M+K = 885; 13 C NMR (75 MHz) delta (selected signals) 196.7, 161.6, 133.6, 118.5, 74.9; IR (KBr) cm" 1 3450, 2930, 1745, 1720, 1650, 1450, 1100. Example 383: Formula VIE: R= ethyl: R'= H: n= 1: R 3 -! and R2 - taken together form a bond: R 3 - 2 - = R 3 - 4 - = H: R 3 -^ and R-3& taken together form an oxo group. The product of Example 36 (502 mg, 0.646 mmol) was dissolved in anhydrous tetrahydrofuran (40 mL). Potassium hydride (193 mg, 1.61 mmol as a 35% suspension in mineral oh) was added and the reaction stirred at room temperamre. After 19 hours, an additional aliquot of potassium hydride (76mg, 0.646 mmol) was added fohowed by quenching 7 hours hence. The tetrahydrofuran was removed, and die material partitioned between 25 mL of 1 N hydrochloric acid and 25 mL of ethyl acetate. The aqueous phase was washed witii an additional 15 mL of etiryl acetate. The organic phases were combined, washed with 20 mL of brine, dried over magnesium sulfate and freed of solvent This material was flash chromatographed on sihca gel eluting with 30% acetone in hexane. Yield 59mg: MS (FAB) mle: M+K = 812; 13 C NMR (125 MHz) delta (selected signals) 96.4, 80.1, 75.2; IR (KBr) cm- 1 3430, 2920, 1755, 1735, 1690,1625, 1455, 1090. Example 384: Formula VIE: R= ethyl: R'= H: n= 1 : R 3 -! and R-2-- taken together form a bond: R32. = RM = H: one of R25 or R3≤= H and the other = -OH. The product of Example 224 (102 mg, 0.128 mmol) was dissolved in tetrahydrofuran (10 mL). Potassium hydride (20 mg, 0.462 mmol) as a 35% suspension was added, and die reaction mixture was stirred at room temperature for 20 hours. The mixmre was quenched witii water (0.5 mL) and concenttated under reduced pressure. The residue was partitioned between 0.5 N hydrochloric acid and etiiyl acetate (50 mL). The aqueous phase was washed again witii ethyl acetate (25 mL), and die combined organic washes were dried over magnesium sulfate and freed of solvent. The crade material was purified by flash chromatography sihca gel eluting with 30% acetone in hexanes. Yield 50 mg: MS (FAB) mle: M+K = 814; 13 C NMR (125 MHz) (delta, selected signal) 202.8, 76.4, 75.8, 74.5, 71.8. Example 385: Formula V: R= ethyl: R'= H: n= 1 : Rl= tgrt-butyldimethylsiloxy: R.31 and R23- taken together form a bond: R-22 = R = H: one of 2-5 and R2≤= H and die other is -OCfQ-lCHoCH The product of Example 36 was dehydrated and the pendant cyclohexanol hydroxyl group protected as its t-butyldimethylsilyl etiier as described in Example 8a. Propionic acid (50 microliters, 0.673 mmol) was dissolved in hexane (10 mL) and N,N-dimethylformamide (50 micoliters). To this, oxalyl chloride (0.29mL, 3.37 mmol) was added, and the reaction mixmre stirred at room temperature for 1 hour. The salts were then removed by filtration, and the solvent removed in vacuo. The freshly made acid chloride was taken into anhydrous methylene chloride (10 mL). The hydrated, protected ascomycin derivative described above (202mg, 0.225 mmol) was added along with diisopropylethylamine (0.2 mL, 1.13 mmol). After 48 hours, the dichloromethane was removed and the material partitioned between IN hydrochloric acid (30 mL) and ethyl acetate (30 mL). The aqueous layer was washed with an additional ethyl acetate (15 mL). The organics were combined, washed witii brine and dried over magnesium sulfate. The solvent was then removed and the material flash chromatographed on sihca gel eluting with 25% acetone in hexane. Yield 101 mg: MS (FAB) mle: M+K = 946. Example 386: Formula El: R= ethyl: R'= H: n= 1: R21= R-i2 = R24=H: R22= -CHC-I^Et: R21 and R36 taken together are =N- which is attached to C22 and the unoccupied valence of the methine on R - 3 - to form a cyclic imine. The 4-chlorobenzylimine of glycine ethyl ester (1.46 g, 6.46 mmol) was dissolved in 80 mL of anhydrous tetrahydrofuran. To this, 0.39 g (9.70 mmol) of sodium hydride as a 60% suspension in mineral oh was added. These were allowed to stir at room temperature for 15 min, before adding 2.00 g (2.58 mmol) of the product of Example 36. After 24 hours at room temperature, the reaction was quenched by die addition of 10 mL of water. The tetrahydrofuran was removed, and the residue loaded onto silica gel and eluted witii 25% acetone in hexane. Yield 0.60 g: MS (FAB) mle: M+K= 897, M+H= 859. Example 387: Formula IE: R= ethyl: R'= H: n= 1: RH= -CH(NH(-))p-chlorophenyl in which the unoccupied valence of the amine and the unoccupied valence on R 3 - 3 - forming a pyrrolidine: The product of Example 36 (501 mg, 0.464 mmol) and die 4-chlorobenzylimine of glycine ethyl ester (218 mg, 0.97 mmol) were dissloved in 20mL anhydrous tetrahydrofuran. To this, 1.40 mL (9.69 mmol) of triethylamine and 265 mg (3.04 mmol) of lithium bromide were added. The reaction was stirred at room temperature under nittogen. After 3 hours, the reaction was poured into 20 mL of IN hydrochloric acid and 20 mL of ethyl acetate. The aqueous phase was washed witii an additional 20 mL of ethyl acetate. The organic washes were combined and washed with 15 mL of brine. The organic layer was dried over magnesium sulfate and freed of solvent to give 0.70g crude material. This material was recrystallized from 2: 1 etiiyl acetate/hexane to give 0.23g of the title compound: MS (FAB) mle: M+K= 1037, 1039, M+H= 999, 1001; 13 C NMR (75 MHz) delta (selected signals) 167.6, 141.7, 135.8, 129.4, 128.9, 63.1, 62.9, 51.8, 50.4; El (KBr) cm" 1 3430, 2930, 1745, 1650, 1450, 1090. Examples 388a and 388b: Formula IE: R = ethyl: R' = H: n = 1: R 3 -! = R 3 ^ = R = H: R25 and R36 taken together form =NMefO) CB- and Z-Configurations) Ascomycin (15 g), triethylamine (9.1 g) and N-mediylhydroxylamine hydrogen chloride (7.5 g) in ethanol (60 mL) were stirred at 45 °C for 60 hours. Solvent was removed in vacuo and die product purified on sihca gel eluting with 10% edianol/dichloromethane. Tide compound of Example 388a: Yield: 10.2 g; MS(FAB) miz: M+K = 859. Tide compound of Example 388b: Yield: 3.5 g; MS(FAB) miz: M+K = 859. Example 391: Formula I: R = ethyl: R' =H: n =l: Rl = -Q-allyl Ql-Configuration). Silver (T) oxide (0.6 g) was added into a stirred solution of ascomycin (0.4 g) and allyl iodide (0.6 g) in acetonitrile (0.5 mL) at 0 °C. After being stirred at room temperamre overnight, the reaction mixture was poured over a column of sihca gel (2 g) in ether and eluted witii etiier. The semi-pure product was purified by sihca gel chromatography (10 g) eluting witii 2% ϊsopropanol/dichloromethane. Yield: 0.245 g; MS(FAB) mz: M+NH 4 = 849. Example 392: Formula I: R = ethyl: R' = H: n = 1: Rl = 4-(N-morphohno-2-ttans- butenvD-O- CR Configuration). Silver Q oxide (0.6 g) is added into a stirred solution of ascomycin (0.4 g) and 4-(N- morpholino-2-ttans-butenyl)-bromide (0.6 g) in acetonitrile (0.5 mL) at 0 °C. After being stirred at room temperature overnight the reaction mixture is poured over a column of sihca gel (2 g) in ether and eluted with ether. The semi-pure product is purified by sihca gel chromatography (10 g) eluting with 2% isopropanol dichloromethane. Example 393: Formula I: R = ethyl: R' = H: n = 1: Rl = N-tettazole (S-Configuration). Trifluoromethanesulfbnyl anhydride (0.28 g in dry dichloromethane 1 mL) was added into a stirred solution of ascomycin (0.8 g) and diisopropyletiiyl amine (0.5 g) in dichloromethane (2 mL) at -15 °C. After being stirred for 0.5 hour, tettazole (0.1 g) was added and stirred at room temperature for 24 hours. Solvent was removed in vacuo and die crude purified by sihca gel (40 g) eluting with 40% acetone/hexanes. The product was further purified by sihca gel (40 g) eluting with 3% isopropanol/dichloromethane. Yield: 0.3 g; MS(FAB) miz: M+K = 882. Example 394: In vivo Assay of Biological Activity The immunosuppressant activity of the compounds of the present invention was determined using the human mixed lymphocyte reacion (MLR) assay described by Kino, T. et al. in Transplantation Proceedings. XIX(5):36-39, Suppl. 6 (1987). The results of the assay, shown below in Table 1, demonstrate that the compounds tested are effective immunomodulators at sub-micromolar concentrations. Table 1 It is understood that the foregoing detailed description and accompanying examples are merely ihusttative and are not to be taken as limitations upon the scope of the invention, which is defined solely by the appended claims and tiieir equivalents. Various changes and modifications to the disclosed embodiments wih be apparent to those skihed in die art Such changes and modifications, including without limitation those relating to the chemical structures, substiments, derivatives, intermediates, syntheses, formulations and/or metiiods of use of die invention, may be made witiiout departing from the spirit and scope thereof.

Claims: We claim: 1. A compound having die formula or a pharmaceutically acceptable salt ester, amide or prodrug thereof, wherein n is zero or one; R and R' are chosen such that (a) one of R and R' is hydrogen and die otiier is selected from the group consisting of methyl, ethyl, 2-hydroxyethyl, propyl, cyclopropylmetiiyl, 2-oxopropyl, 2-ethanal, allyl, -CH 2 CH 2 OC(0)R 10 where R 10 is aryl, -CH 2 C(0)R 12 , -CH 2 C(0)N(R 1 ' )(CH 2 ) m CH(R 16 )-C(0)R 12 , -CH 2 C(0)N(R 4 ')(CH 2 ) m CH(R 1 6)C(0)- N(R 1 ")(CH 2 ) m €H(R 16' )C(0)R 12 , and -CH 2 C(0)N(R 14 ')(CH 2 ) m CH(R 16 )C(0)- N(R 14" )(CH 2 ) m €H(R 1 6 ' )C(0)-N(R 1 '" )(CH 2 ) m "CH(R 1 6 " )C(0)R 12 , wherein m, m" and m" are independendy zero to six; R 16 , R 16 ' and R 16 " are independentiy selected from hydrogen, loweralkyl, hydroxyloweralkyl, carboxyalkyl, thioloweralkyl, thioalkoxyalkyl, guanidinoalkyl, aminoalkyl, arylalkyl and, if m, m' and m" are other than zero, amino or amidoalkyl; and R 12 is selected from (i) hydroxy, (ii) -OR 13 where R 13 is loweralkyl, cycloalkyl, cycloalkylalkyl or arylalkyl, and (iii) -NR 14 R 15 wherein R 14 , R 14 ', R 14" and R 14' " are independentiy selected from hydrogen, loweralkyl, arylalkyl, cycloalkyl and cycloalkylalkyl and R 15 is selected from hydrogen, loweralkyl, arylalkyl, cycloalkyl, cycloalkylalkyl, aminoalkyl, hydroxyalkyl, carboxyalkyl, and thioloweralkyl; or, taken together, R 14 and R 15 are -(CH 2 )q- where q is two to five; or, taken together witii the nittogen to which they are attached, R 14 and R 15 form a group selected from morpholino and piperidino; or, taken together, one or more of R 14' and R 16 , R 14 " and R 16 ', and R 14 " and R 16 " are -(CH 2 ) p - where p is two to five, or (b) one of R and R', taken together with one of R 35 and R 36 , forms a C-21/C-22 bond and the other of R and R', taken together with the other of R 35 and R 36 , is a heterocycle-forming group having a formula selected from -N(R 63 )CH=CH- and where the heteroatom in each instance is connected to C-22, R 63 is selected from hydrogen, loweralkyl, arylalkyl and aryl, and R 64 is hydrogen or loweralkyl; X is selected from wherein R 1 is selected from me group consisting of: (a) hydrogen, (b) halogen, (c) triflate, (d) mesylate, (e) tosylate, (f) benzenesulfonate, (g) azide, (g') cyanate, (h) -OC(S)OR 11 , wherein R 11 is selected from loweralkyl, arylalkyl and aryl, (i) -OC(0)R 19 , wherein R 19 is selected from (i) hydrogen, (ii) loweralkyl, (hi) arylalkyl, (iv) aminoalkyl, (v) aryl and (vi) an alpha-carbon with an optionahy protected alpha- amino, and appended side-chain of a standard alpha-amino acid, (j) -OC(0)NHR 17 , wherein R 17 is selected from hydrogen, loweralkyl, arylalkyl, aryl and -SR 14 , (k) -OC(0)OR n , 00 -OP(0)(ORl 1 ) 2 , ( ) -ORll, (n) -0(CH 2 ) j C(0)R 12 , where j is one to five, (0) -0(CH 2 ) j C(0)N(R 14' )(CH 2 ) m CH(R 16 )C(0)R 12 , (p) -0(CH 2 ) j C(0)N(Rl 4 ')(CH 2 ) m CH(R 1 6)C(0)N(R 14 ")(CH 2 ) m ■CH(R 1 6 , )- C(0)R 12 , (q) -0(CH 2 ) j C(0)N(R 14 ')(CH 2 ) m CH(R 1 6)C(0)N(R 14 ")(CH 2 ) m €H(R 1 6')- C(0)N(R 14 '")-(CH 2 VCH(R 16 ")C(0)R 12 , (ee) a group having the formula (Ie) , and (ff) a group having the formula (If) where R 20 and R 20 ' are independently selected from the group consisting of hydrogen, aryl, cyano, trifluoromethyl, - C(0)-0-loweralkyl and -C(0)-loweralkyl, (gg) a group having the formula (lg) , and (hh) hydroxy; R 2 is hydrogen or trifluoromethylcarbonyl or, taken together with R 2 ', forms a diazo group or, taken together with one of R 3 and R 4 , forms a C-32/C-33 bond; R 2 ' is hydrogen or, taken together with R 2 , forms a diazo group; R 3 and R 4 are chosen such that (a) both are thioloweralkoxy, thioaryloxy or thioarylalkoxy; (b) one of R 3 and R 4 is selected from hydrogen, hydroxy and a C-32/C-33 bond formed witii R 2 , and die other of R 3 and R 4 is hydrogen or R 11 ; or (c) taken together, R 3 and R 4 form a group selected from (i) oxo, (ii) =NR 48 where R 48 is selected from arylalkoxy, hydroxy, - 0(CH 2 ) f COOH where f is one to five, -NHC(0)OR 39 where R 39 is loweralkyl, and - NHS(O) 2 R 0 where R 40 is aryl, (hi) =NOR 222 or =N+(0")R 222 , where R 222 is selected from the group consisting of lowerlkyl, aryl, -S0 2 -(loweralkyl) and -S0 2 -(aryl), and (iv) a tirioketal-forming moiety having the formula -S-(CH ) r S- where r is two or three; and R 5 is selected form the group consisting of formyl and -CH2OR 1 ; Y is a group having a structural formula selected from (TEa'), wherein (a) R 31 and R 32 are chosen such that one of R 31 and R 32 is hydrogen and the other is independentiy selected from me group consisting of (i) hydrogen, (ii) hydroxy, (hi) -R 17 , (iv) -C(0)R n and (v) -CH R^NHR 17 ; or, taken together, R 31 and R 32 form a diazo group; or, taken together witii one of R 33 and R 34 , one of R 31 and R 32 forms a C-23/C-24 bond and die other is selected from die group consisting of hydrogen, alkyl, -C(0)NHR 61 , -S(0) 2 R 61 and -C(0)OR 61 , where R 61 is hydrogen, aryl or loweralkyl; or, taken together with one of R 33 and R 34 , one of R 31 and R 32 forms a group having the formula (in C-23 to C-24 orientation) -CH R^NHOE^C^OR 11 )-; or, taken togedier with one of R 35 and R 36 , one of R 31 and R 32 forms a C-22/C-23 bond; or R 31 and R 32 , togedier with carbon atom C-23 to which they are attached, may be absent and replaced by a C-22/C-24 bond; or, taken together with one or both of R 33 and R 34 and die carbon atoms to which they are attached, one or both of R 31 and R 32 form (i) a fused indole group wherein the nittogen atom is adjacent to C-24, (ii) a fused, optionally unsamrated, 5-membered heterocyclic group wherein one of die two ring members adjacent to C-23 and C-24 is oxygen, the other adjacent ring member is -CHR 17 - or =CR 17 -, and the remaining ring member is =N- or -NR 1 *- , or (iii) a fused pyrrole; or, taken together with R 35 and R 36 and the carbon atoms to which they are attached, R 31 and R 32 form (i) a fused indole group wherein the nittogen atom is adjacent to C-22 or (h) a fused furan ring wherein the oxygen atom is adjacent to C-22; (b) R 35 and R 36 are chosen such that both are loweralkoxy, or that one of R 35 and R 36 is hydrogen and the other is selected from hydroxy, amino, -NHR 17 , -OC(0)R n , -OC(0)0-(benzyl) and -NHNH-(tosyl) or, taken together with one of R 31 and R 32 , forms a C- 22/C-23 bond; or, taken together with one of R 33 and R 34 when C-23 is absent, one of R 35 and R 36 forms a C-22/C-24 bond and the other is hydrogen or hydroxy; or, taken together with one of R 33 and R 34 , one of R 35 and R 36 forms a group having the formula -OC(CH 3 ) 2 0-; or, taken together, R 35 and R 36 form an oxo group or =NR 38 where R 38 is selected from (i) arylalkoxy, (ii) hydroxy, (iii) -OCH 2 COOH, (iv) -OCH 2 CHCH 2 , (v) -NHC(0)OR 39 and (vi) -NHS(O) 2 R 4 0; or, taken together with R and R', R 35 and R 36 form a C-21/C-22 bond and a heterocycle- forming group as described above; or, taken together with R 31 and R 32 , R 35 and R 36 form an indol or furan group as described above; or, taken together witii either or botii of R 33 and R 34 and intervening carbon atoms C-22, C-23 and C-24, R 35 and R 36 form a fused, heterocyclic group selected from (i) a five- or six- membered, unsaturated group comprising a heteroatom selected from N, O and S, optionahy comprising a second heteroatom selected from N, O and S witii the proviso that when two heteroatoms are present, at least one is N, and optionally substimted witii loweralkyl, aryl, arylalkyl, amido, formyl, -C(0)OR xl or-C(0)R 41 where R 41 is loweralkyl, and (ii) a seven- membered, optionahy unsamrated group having fused thereto a phenyl group optionahy substimted witii loweralkyl, alkoxy or halogen, wherein the ring member adjacent to C-22 is =N- and die ring member adjacent to C-24 is O or S; and (c) R 33 and R 34 are chosen such tiiat (i) one of R 33 and R 34 is hydrogen and the otiieris selected from hydrogen, hydroxy, amino, -OR 11 , -ON0 2 , -OC(0)NHR 17 , -C(0)R π , and -0-(hydroxyl protecting group); (h) one of R 33 and R 34 is hydrogen and die otiier forms, with one of R 31 or R 32 , a group having the formula -CH(RH)NHCH(C(0)OR n )- or, with one of R 35 and R 36 , a group having the formula -OC(CH 3 ) 2 0-; or (hi) one of R 33 and R 34 forms a C-23/C-24 or , when C-23 is absent, a C-22/C-24 bond and die otiier is selected from hydrogen, hydroxy and loweralkoxy; or, taken together, R 33 and R 34 form an oxo group; or, taken together with one or more of R 31 , R 32 , R 35 and R 36 and the intervening carbon atoms, one or both of R 33 and R 34 form a group selected from (i) indole, where the nittogen atom is adjacent to C-24, (ii) furan, with the oxygen atom attached to C-24, or (hi) a heterocyclic group as described above; and Z is selected from (na) and (Eb), wherein (a) ' R 21 and R 22 are chosen such that (i) one of R 21 and R 22 is hydrogen and the other is selected from hydrogen, loweralkyl, arylalkyl, aryl, halogen, triflate, mesylate, tosylate, benzenesulfonate, azide, amine, acetate, -NR 17 R 18 , -OC(0)R 19 , -NR 17 S(0) 2 R 18 , -NR 17 C(0)R 18 , and groups having the formulae (Ig) or, taken together with R 23 , forms a C-9/C-10 bond, or (ii) one of R 21 and R 22 is hydroxy and the other is selected from hydrogen, loweralkyl, arylalkyl and aryl, or (hi) one of R 21 and R 22 is selected from hydrogen, loweralkyl and arylalkyl and the otiier, taken together with R 23 and the carbon atoms to which they are attached, forms a fused, five membered heterocyclic group wherein the two ring members adjacent C-9 and C-10 are oxygen and die remaining ring member is selected from -C(O)- and -C(S)-, or (iv) one of R 21 and R 22 is selected from hydrogen, loweralkyl and arylalkyl and the other, taken together with R 23 and the carbon atoms to which they are attached, forms a fused, five-membered heterocyclic group wherein the two ring members adjacent to C-9 and C-10 are oxygen and the remaining ring member is -P(0)(R 25 )- where R 25 is loweralkyl, arylalkyl, loweralkoxy, amino or loweralkylamino; or, taken together, R 21 and R 22 form a group selected from oxo, oxime and -0-CH 2 -; or wherein R 21 and R 22 and the carbon to which they are attached are absent and C-8 is directiy attached to C-10; (b) R 23 is selected from me group consisting of hydroxy, halogen, amino, loweralkylamino, arylalkylamino, loweralkoxy and arylalkoxy or, taken together with one of R 21 and R 22 , forms a C-9/C-10 bond or, taken together with R 24 , forms a C-10/C-ll bond; (c) R 24 is hydrogen or, taken together with R 23 , forms a C-lO/C-11 bond; (d) R 26 , R 27 , R 28 and R 29 are chosen such that (i) one of R 28 and R 29 is hydroxy and the other is -COOH or -C(0)0-loweralkyl, and (ii) R 26 and R 27 and die carbon to which tiiey are attached are absent and C-8 is directiy attached to C-10; or, taken together, R 26 and R 27 are oxo while one of R 28 and R 29 is hydroxy and die otiier forms a C-2/C-10 bond; or, taken together, R 26 and R 28 form a bond and R 27 and R 29 form a group having the formula -U-C(R 11 )=N- wherein U is adjacent to C-9 and is selected from -0-, -S- and -NH-; or R 26 and R 28 are each hydroxy and R 27 and R 29 , taken together, form a group having die formula -CH 2 -C(CH 2 )-CH 2 -; or, taken together with the carbon atoms to which they are attached, R 26 , R 27 , R 28 and R 29 form (i) a fused naphtiialene group wherein the atoms adjacent to C-9 and C-10 are substimted by cyano groups, or (ii) a fused, mono-, bi- or tricyclic heterocychc aromatic group comprising fused, six-membered rings, which has between one and tiiree nittogen heteroatoms and is optionahy substimted with up to six groups selected from amino, halogen, loweralkyl and loweralkoxy; and (e) R 6 0 and R 65 are chosen such that R 5 is hydrogen and R 60 is selected from me group consisting of (i) hydrogen, (ii) hydroxy and (ih) -OC(0)R 19 or, taken together, R 60 and R 65 form an oxo group. 2. A compound according to Claim 1 having the formula wherein R' is hydrogen and n, R, X and Z are as defined above. A compound according to Claim 1 having the formula wherein n, R, R', X and Y are as defined above. A compound according to Claim 1 having the formula wherein n, R, R', Y and Z are as defined above. A compound according to Claim 2 having the formula wherein R' is hydrogen and n, R and X are as defined above. 6. A compound according to Claim 5 wherein X is a group having the formula wherein R 221 is selected from =NOR 222 and =N + (0 _ )R 222 , where R 222 is the group consisting of lowerlkyl, aryl, -S0 -(loweralkyl) and -S0 2 -(aryl). 7. A compound according to Claim 2 having the formula wherein R' is hydrogen and n, R and Z are as defined above. 8. A compound according to Claim 4 having the formula wherein n, R, R' and Y are as defined above. 9. A compound according to Claims 1, 3, 4 or 8 wherein Y is selected from the group consisting of wherein R 11 , R 17 , R 31 , R 32 , R 38 and R 41 are as defined above; R 81 is selected from hydrogen, alkyl, -C(0)NHR 61 , -S(0) 2 R 61 and -C(0)OR 61 ; R 82 and R 83 are independently selected from hydroxy and amino; R 84 is hydrogen, hydroxy or loweralkoxy; R 85 is hydrogen or hydroxy; R 86 is selected from hydrogen, loweralkyl, aryl, arylalkyl, amido, formyl, -C(0)R 41 and -C(0)OR 41 ; R 87 is selected from hydrogen, halogen, alkoxy and loweralkyl; V is selected from oxygen, -N(R 86 )- and -NC(0)R 86 - ; and W is oxygen or sulfur. 10. A compound according to Claims 1, 2, 4 or 7 wherein Z is selected from the group consisting of wherein R 11 , R 21 , R 22 , R 23 and U are as defined above; R 70 is hydrogen, loweralkyl or arylalkyl; R 71 is hydrogen or loweralkyl; R 72 is oxygen or sulfur; and A, D, E, G, J and are selected from nitrogen, carbon and -C(R 73 )- where R 73 is amino, halogen, loweralkyl or loweralkoxy. 11. A pharmaceutical composition useful for immunomodulation, comprising a therapeutically effective amount of a compound of Claim 1 in combination with a pharmaceutically acceptable carrier.

Inventors: KAWAI MEGUMI, LULY JAY R, OR YAT SUN, WAGNER ROLF, WIEDEMAN PAUL, KAWAI, MEGUMI, LULY, JAY, R., OR, YAT, SUN, WAGNER, ROLF, WIEDEMAN, PAUL
Applicants: ABBOTT LAB, ABBOTT LABORATORIES
Application year: 1992
Main classification: A61K31
IPC codes: A61K31, A61P1, A61P17, A61P21, A61P29, A61P37, C07D487, C07D491, C07D498, C07D513, C07F7, C07F9, C07H19