NOVEL 6 OR 7 SUBSTITUTED ANALOGUES OF SWAINSONINE, PROCESSES FOR THEIR PREPARATION AND THEIR USE AS THERAPEUTIC AGENTS

Abstract: The invention relates to 6 or 7 substituted swainsonine analogues, processes for their preparation and their use as therapeutic agents. The invention also relates to pharmaceutical compositions containing the compounds and their use as therapeutics.

Description: Title: NOVEL 6 OR 7 SUBSTITUTED ANALOGUES OF SWAINSONINE, PROCESSES FOR THEIR PREPARATION AND THEIR USE AS THERAPEUTIC AGENTS FIELD OF THE INVENTION The present invention relates to novel 6 or 7 substituted analogues of swainsonine, processes for their preparation, and their use as therapeutic agents. BACKGROUND OF THE INVENTION Carbohydrate structures present on human tumor cells have been associated with cancer invasion and metastasis (Dennis et. al., Science 236: 582, 1987; Demetriou et. al., J. Cell Biol. 730:383, 1995). These structures include the GlcNAc β(Tl-6) branched N- and O-linked carbohydrate side chains of cell-surface glycoproteins. The Golgi enzymes required for their synthesis are β(Tl-6) aV-acetylglucosaminyltransferase V (i.e. GlcNAc-TV) and core 2 β(Tl-6) -V-acetylglucosaininyltransferase (i.e. core 2 GlcNAc-T), respectively. These enzymes are up-regulated in human carcinomas (Fernandes et al., Cancer Res. 51:718-723, 1991), a phenomenon that has been associated with the activation of the ttts signaling pathway (Dennis et al., Science 236:582-585, 1987; Dennis et al Oncogene 4:853-860, 1989)). Furthermore, overexpression of GlcNAc-TV in epithelial cells results in morphological transformation and tumor formation in mice (Demetriou et al, J. Cell Biol. 130:383-392, 1995). Therefore, GlcNAc-TV as well as enzymes supplying acceptor substrates to GlcNAc-TV (i.e. GlcNAc-TI, α-mannosidase II and core 2 GlcNAc-T of the O-linked pathway) are targets for anti-cancer pharmaceuticals. Although there are no inhibitors of GlcNAc-TV presently available, a lead α-mannosidase II inhibitor, swainsonine has been tested in preclinical and human trials. Swainsonine is an indolizidine alkaloid found in Australian Swainsona canescens (Colegate et al., Aust J Chem 32:2257-2264, 1979), North American plants of the genera Astragalus and Oxytropis (Molyneux RJ and James LF., Science 215:190-191, 1981), and also the fungus Rhizoctonia leguminicola (Schneider et al., Tetrahedron 39;29-31, 1983). Swainsonine's ability to inhibit OC-mannosidase II activity appears to be responsible for its interesting immunomodulating and cancer suppression activity. Swainsonine is believed to function as an enzyme inhibitor because it can mimic the glycosylium cation intermediate generated during the hydrolytic cleavage of mannopyranosides. (Goss, P.E. et al., Clin. Cancer Res. T. 935-944, 1995). The swainsonine blockage of α-mannosidase II is prior to GlcNAc-TV and prevents expression of GlcNAc β(Tl-6) branched /V-linked carbohydrates. Swainsonine-treated murine tumor cells have been found to be less metastatic in both organ-colonization and spontaneous metastasis assays in mice (Dennis J.W., Cancer Res. 46:5131-5136, 1986 and Humphries et al., Proc. Natl. Acad. Sci. USA 83:1752-1756, 1986). Swainsonine has also been shown to block tumor cell invasion through extracellular matrix in vitro (Yegel et al., Int. J. Cancer 44:685-690, 1989 and Seftor et al., Melanoma Res. 1:53-54, 1991). Swainsonine administered either orally or by mini-osmotic pumps to athymic nude mice inhibited the growth rate of human MeWo melanoma and HT29m colon carcinoma tumor xenografts in the mice (Dennis et al., J. Natl. Cancer Inst. 81:1028-1033, 1989 and Dennis et al., Cancer Res., 50:1867-1872,1990). Phase 1 clinical trials of swainsonine have been done which indicate that it has efficacy in the treatment of human tumors. (Goss et. al, Cancer Res., 54: 1450, 1995). Although side-effects in humans are mild, some of these may be associated with swainsonine's inhibition of lysosomal storage of carbohydrates. Swainsonine has positive effects on cellular immunity in mice (reviewed in Humphries M.J. and Olden K., Pharmacol Ther. 44:85-105, 1989, and Olden et al., Pharmacol Ther 50:285-290, 1991)). In particular, swainsonine has been shown to alleviate both chemically-induced and tumor-associated immune suppression (Hino et al., J. Antibiot. (Tokyo) 38:926-935, 1985), increase NK cell (Humphries et al., Cancer Res. 48: 1410-1415, 1988), and LAK cell activities (Yagita M and Saksela E., Scand. J. Immunol. 31 :275-282, 1990), and increase splenic and bone marrow (BM) cell proliferation (White et al., Biochem. Biophys. Res. Commun. 150;615-625, 1988; Bowlin et al. Cancer Res 49, 4109-4113, 1989, and White et al., Cancer Commun. 3:83-91, 1991). SW has also been shown to be hemorestorative in mice following treatment with both cycle-specific and nonspecific chemotherapeutic agents (Oredipe et al., J. Natl. Cancer Inst. 83:1149-1156, 1991). Japanese Patent Application No. J61277685 describes indolizidine derivatives which are reported to be useful as immune regulators, which can be administered orally or parenterally at a dose of about 0.1- 100 ml/kg a day. It is also reported that the indolizidine derivatives may be used in combination with antitumour agents, antimicrobial agents or antiinflammatories. Carbonoyloxy substitutions at the 2 and 8 carbons of swainsonine have been reported to reduce inhibitor activity by 2-3 orders of magnitude for Jack Bean and MDAY-D2 tumor cell lysosomal mannosidases in vitro. However, 2-p-nitrobenzoyloxy, 2-octanoyloxy- and 2-butanoyloxy-derivatives of swainsonine retained full activity as inhibitors of Golgi oligosaccharide processing in viable MDAY-D2 tumor cells. Inhibition of oligosaccharide processing was reduced by the esterase inhibitor diethyl p- nitrophenyl phosphate, suggesting that while the compounds are relatively poor inhibitors of mannosidase in vitro, the compounds enter cells at a rate comparable to that of swainsonine and are converted to swainsonine by cellular esterases. The more lipophilic esters, 2-benzoyloxy-swainsonine, 2-toluoyloxy- swainsonine, 8-palmitoyloxy-swainsonine and 8-myristinoyloxy-swainsonine, showed IC 50 values at least 10 times higher for inhibition of Golgi oligosaccharide processing, probably due to less efficient entry of the compounds into tumor cells. The anti-metastatic activities of swainsonine and two analogs were tested and shown to correlate with the IC 50 values for inhibition of Golgi oligosaccharide processing in cultured tumor cells. In vivo, SW and the analogs were administered intraperitoneally to mice and found to have comparable activities as stimulators of bone marrow cell proliferation. (Dennis, J. W. et al. Biochemical Pharmacology 46:1459-1466, 1993). Selected swainsonine analogues, in particular 2-substituted analogues, and methods for preparing the analogues are described in U.S Patent No. 5,466,809. SUMMARY OF THE INVENTION The present inventors have found that selective derivatization of swainsonine at the 6 or 7 position provides analogues of swainsonine which are ideally suited for use as therapeutic agents having improved pharmacological properties and reduced side effects. Particular analogues at the 6 or 7 position were found to selectively inhibit the Golgi α-mannosidase π activity over its lysosomal counteφart. This selectivity avoids undesirable properties which can be exhibited by swainsonine. The present invention therefore relates to a compound of the formula I wherein (a) R 1 , R 3 and R 5 are the same or different and represent hydrogen, alkyl, or aryl; (b) R 2 , R 4 and R 6 represent hydroxyl or alkoxy; and (c) one of Y and Y' represents hydroxyl, alkyl, cycloalkyl, alkenyl, alkynyl, an unsaturated monocyclic hydrocarbon, aryl, alkoxy, or aryloxy, and the other of Y and Y' represents hydrogen, and Z and Z' represent hydrogen; or, one of Z and Z' represents alkyl, cycloalkyl, alkenyl, alkynyl, an unsaturated monocyclic hydrocarbon, aryl, alkoxy, or aryloxy and the other of Z and Z' represents hydrogen, and Y and Y' represent hydrogen. The present invention also provides a process for the preparation of a compound of the formula I as defined herein, and a pharmaceutical formulation comprising a compound of the formula I as an active agent. The invention further relates to a method for stimulating the immune system, treating proliferative disorders, or microbial infections in a patient comprising administering an effective amount of a compound of the formula I of the invention. The invention also relates to the use of a compound of the formula I in the preparation of a medicament for stimulating the immune system, and/or for treating proliferative disorders, and microbial infections. The present invention also relates to the use of a compound of the formula I which is esterified at free hydroxyls as a prodrug. These and other aspects of the present invention will become evident upon reference to the following detailed description and attached drawing. In addition, reference is made herein to various publications, which are hereby incorporated by reference in their entirety. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in relation to the drawings in which: Figure 1 are schematic diagrams of reactions for preparing analogues of the invention. DETAILED DESCRIPTION OF THE INVENTION I. COMPOUNDS OF THE INVENTION Hereinabove and in the following the term "alkyl", alone or in combination, refers to a branched or linear hydrocarbon radical, typically containing from 1 through 20 carbon atoms, preferably 1 through 15. Typical alkyl groups include but are not limited to methyl, ethyl, 1-propyl, 2-propyl, 1- butyl, 2-butyl, tert-butyl, pentyl, hexyl, and the like. The term "alkenyl", alone or in combination, refers to an unsaturated branched or linear group typically having from 2 to 20 carbon atoms and at least one double bond. Examples of such groups include but are not limited to ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 1 ,3-butadienyl, hexenyl, pentenyl, and the like. The term "alkynyl", alone or in combination, refers to an unsaturated branched or linear group having 2 to 20 carbon atoms and at least one triple bond. Examples of such groups include but are not limited to, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, and the like. The term "cycloalkyl" refers to cyclic hydrocarbon groups and includes but is not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. The terms "cycloalkenyl" and "cycloalkynyl" refer to unsaturated monocyclic hydrocarbons having one endocyclic double or one triple bond. Compounds of the formula I having more than one such multiple bond are cycloalkadienyl, cycloalkatrienyl, etc. The inclusive term for any cyclic hydrocarbons having any number of such multiple bonds is unsaturated monocyclic hydrocarbons. Examples of unsaturated monocyclic hydrocarbons are cyclohexene, cyclopentadiene, and cyclooctadiene. The term "aryl", alone or in combination, refers to a monocyclic or polycyclic group, preferably a monocyclic or bicyclic group. An aryl group may optionally be substituted as described herein. Examples of aryl groups and substituted aryl groups are phenyl, benzyl, p-nitrobenzyl, p-methoxybenzyl, biphenyl, and naphthyl. The term "alkoxy" alone or in combination, refers to an alkyl or cycloalkyl linked to the parent molecular moiety through an oxygen atom. The term "aryloxy" refers to an aryl linked to the parent molecular moiety through an oxygen atom. Examples of alkoxy groups are methoxy, ethoxy, propoxy, vinyloxy, allyloxy, butoxy, pentoxy, hexoxy, cyclopentoxy, and cyclohexoxy. Examples of aryloxy groups are phenyloxy, O-benzyl i.e. benzyloxy, O-p-nitro-benzyl and O-p-methyl-benzyl, 4-nitrophenyloxy, 4- chlorophenyloxy, and the like. One or more of R', R 2 R 3 , R 4 , R 5 , R 6 , Y, Y', Z, and/or Z', alone or together, which contain available functional groups as described herein may be substituted with for example one or more of the following: alkyl, alkoxy, hydroxyl, aryl, cycloalkyl, alkenyl, alkynyl, or unsaturated monocyclic hydrocarbons. The term "one or more" used herein preferably refers to from 1 to 3 substituents, most preferably 1 to 2 substituents. In an embodiment of the invention, compounds of the formula I are provided where R 1 , R 3 , and R 5 are the same and represent hydrogen, and R 2 , R 4 , and R 6 are the same and represent hydroxyl. Preferred compounds of the formula I of the invention are those where (a) R 1 , R 3 , and R 5 represent hydrogen, and R 2 , R 4 , and R 6 represent hydroxyl, and Z and Z' represent hydrogen, one of Y and Y' represents methyl, ethyl, phenyl, benzyl, methoxy, or 2-benzyloxy ethyl, and the other of Y and Y' represents hydrogen, or (b) where R 1 , R 3 , and R 5 represent hydrogen, and R 2 , R 4 , and R 6 represent hydroxyl, and Y, and Y' represent hydrogen, one of Z and Z' represents methyl, ethyl, phenyl, benzyl, methoxy, or 2-benzyloxyethyl, and the other of Z and Z' represents hydrogen. Particularly preferred compounds of the invention are (lS,2R,6S,8R,8aR)-6-Ethyl-l,2,8 trihydroxyindolizidine [(6S)-6-Ethyl-swainsonine]; (lS,2R,6R,8R,8aR)-6-Ethyl-l,2,8- trihydroxyindolizidine [(6S)-6-Ethyl-swainsonine]; (lS,2R,6R,8R,8aR)-6-[2-(Benzyloxy)ethyl]-l,2,8- trihydroxyindolizidine [(6R)-6-(2-Benzyloxyethyl)-swainsonine]; (lS,2R,7R,8R,8aR)-7-Butyl- 1,2,8- trihydroxyindolizidine [(7R)-7-Butyl-swainsonine] (304); (lS,2R,7R,8S,8aS)-7-Butyl-l,2,8- trihydroxyindolizidine [(7R)-7-Butyl-8,8a-diepiswainsonine] ; ( 1 S,2R,7R,8R,8aR)-7-[2-(Benzyloxy)ethyl]- 1,2,8-trihydroxyindolizidine [(7R)-7-(2-Benzyloxyethyl)swainsonine]; (lS,2R,7S,8S,8aS)-7-Butyl-l,2,8- trihydroxyindolizidine [(7S)-7-Butyl-swainsonine]; (lS,2R,7S,8S,8aS)-7-Butyl-l,2,8-trihydroxyindolizidine [(7S)-7-Butyl-8,8a-diepiswainsonine]; (lS,2R,7S,8R,8aR)-7-[2-(Benzyloxy)efhyl]-l,2,8- trihydroxyindolizidine [(7S)-7-(2-Benzyloxyethyl)swainsonine]; and (lS,2R,7S,8R,8aR)-7-[2- (Benzyloxy)ethyl]- 1 ,2,8-trihydroxyindolizidine [(7S)-7-(2-Benzyloxyethyl)swainsonine] . It will be appreciated that, owing to the asymmetrically substituted carbon atoms in formula I, a compound of formula I may exist in, and be isolated in, optically active and race ic forms. It is to be understood that the present invention encompasses a compound of formula I as a mixture of diastereomers, as well as in the form of an individual diastereomer, and that the present invention encompasses a compound of formula I as a mixture of enantiomers, as well as in the form of an individual enantiomer. It will be appreciated that the (S)-isomer and the (R)-isomer are convertible by facile epimerization of the chiral centers, and that a preparation containing a compound of formula I as a mixture of the (S)- and (R)- isomers of the formula I is within the scope of the invention. Therefore, the present invention contemplates all optical isomers and racemic forms thereof of the compounds of the invention and the formulas of the compounds shown herein are intended to encompass all possible optical isomers of the compounds so depicted. The present invention also contemplates salts and esters of the compounds of the formula I of the invention. In particular, the present invention includes pharmaceutically acceptable salts. By pharmaceutically acceptable salts is meant those salts which are suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit risk ratio. Pharmaceutically acceptable salts are well known in the art and are described for example, in S. M. Berge, et al., J. Pharmaceutical Sciences, 1977, 66: 1-19. II. PROCESSES FOR PREPARING COMPOUNDS The compounds of the formula I of the present invention can be prepared by utilizing procedures and techniques well known and appreciated by one of ordinary skill in the art. By way of illustration, descriptions of some methods that may be used to prepare compounds of the formula I of the invention are set forth herein. Compounds of the Formula I may be synthesized in a variety of ways by adapting common synthetic organic chemistry practices to known synthetic intermediates. For example, analogues containing the basic swainsonine skeleton and alkyl or aryl substituents at positions 6 or 7 can be prepared by reacting a suitably protected eryfhrose derivative (e.g. 2, 3-0-isopropylidene D-erythrose) with a suitable vinyl Grignard reagent or a suitable alkynyl Grignard reagent followed by partial reduction over Lindlar's catalyst. The resulting primary hydroxyl group is selectively protected and the corresponding allylic alcohol subjected to a Claisen rearrangement reaction using a suitable ortho ester, an acid catalyst and heat. With the new ester/alkene in hand, the protected primary hydroxyl group is transformed to azide and the alkene is derivatized by asymmetric dihydroxylation or epoxidation. Ring cyclization by hydrogenation of the azido epoxide ester followed by borane reduction of the resulting amide and complete deprotection gives rise to 6 or 7 substituted swainsonine derivatives depending on the Grignard reagent and/or the orthoester used. Alternatively, reduction and cyclization of the azido diol ester followed by deprotection can also afford the same derivatives. (See Figure 1). Reactive groups used in processes for preparing the compounds of the invention, may be blocked using appropriate protective groups. Appropriate blocking and deblocking schemes are known to the skilled artisan (See T.W. Greene, Protective Groups in Organic Synthesis , John Wiley & Sons, New York, 1981). In general, particular protective groups are selected which adequately protect the reactive groups in question during subsequent synthetic steps and which are readily removable under conditions which will not cause degradation of the desired product. By way of example, ethers, acetals, ketals, and esters can be used to protect isolated hydroxyl groups. In particular, suitable protective groups which may be used in the process of the invention include O-benzyl, O-p-methoxybenzyl, O-acetoxy, O-haloacetoxy, O-benzoyloxy, and O-allyl. Removal of the protective groups may be carried out using procedures known in the art. For example, a p-methoxybenzyl group may be removed using eerie ammonium nitrate in acetonitrile and water. Appropriate methods for replacing a free hydroxyl group by alkoxy in blocked/deblocked compounds to produce compounds where for example R 2 , R 4 and R 6 are alkoxy, are well known to the skilled artisan. In particular, a free hydroxyl group may be converted to an alkoxy group by reacting with alkyl or aryl halide in the presence of a base. An alkoxy group may be added by dissolving a compound with a free hydroxyl in DMF and adding it to a flask under an inert atmosphere containing a base (e.g. sodium hydride) at low temperature (0°C to 10°C). After stirring for a few minutes, benzyl bromide in DMF is added dropwise at low temperature, for example 0°C to 10°C. The reaction mixture is further stirred at room temperature for 2 to 24 hours. Conventional work-up of the reaction mixture yields the alkoxy (benzyl) compound. In addition, appropriate methods for replacing a blocked or deblocked hydroxyl group with a hydrogen in compounds of the formula I are well known to the skilled artisan. For example, alkyl halides or sulfonyl esters such as tosylates can be selectively reduced with lithium aluminum hydride or a variety of other metal hydride reducing agents in different solvents such as ether or diglyme. A large list of methods able to achieve this transformation is provided in J. March "Advanced Organic Chemistry. Reactions, Mechanisms and Structure" 4th Edition, 1992, pp 438- 446 and references cited therein. Some alkyl or aryl groups, particularly those which may contain unsaturations or other chemical functional groups such as hydroxyl, or alkoxy for example, can be further derivatized by chemical processes such as oxidation, hydroxylation, hydrolysis, alkylation, reduction, carbon-carbon chain elongation by Grignard or Wittig reactions for example to introduce new or additional functional groups in any final compound. Such transformations can be achieved by anyone skilled in the art of synthetic organic chemistry. If necessary, the products of the processes described above may be purified by conventional methods such as column chromatography. Compounds of the formula I with available hydroxyl groups can be converted to epi-isomers by SN 2 inversion. For example, the free hydroxyl can be reacted with mesyl chloride and pyridine to give O-mesyl (methyl sulphonyl), which on treatment with sodium benzoate in DMF (dimethyl formamide) produces a compound where the free hydroxyl group is replaced by epi-O-benzoate. Deesterification using NaOMe in methanol results in a compound of the formula I where the free hydroxyl is replaced by epihydroxyl. The compounds of the formula I described above may be converted into salts using conventional procedures. Compounds of the formula I with free hydroxyl groups may also be converted into esters using conventional procedures. For example, the compounds of the formula I may be dissolved in DCM and pyridine. After cooling (0°C to 5°C) benzoic anhydride or benzoyl chloride in DCM and pyridine is added dropwise. The reaction is allowed to stir at room temperature for 2 to 24 hours. Conventional work-up yields the esterified derivatives. Optical antipodes of the compounds of the formula I may be prepared from the corresponding racemic forms by standard optical resolution techniques, involving, for example, the separation of diastereomeric salts of those compounds of the formula I characterized by the presence of a basic amino group, and an optically active acid, or by synthesis from optically active precursors. ///. UTILITY OF COMPOUNDS OF THE INVENTION The compounds of the formula I are inhibitors of oligosaccharide processing and in particular are inhibitors of mannosidase. General mannosidase inhibition may be tested by measuring the inhibition of Jack Bean, α-mannosidase, and lysosomal α-mannosidase. Mannosidase inhibition may also be tested using an L-PHA toxicity assay. The assay is based on the finding that the specific binding of the toxic plant lectin L-PHA to transformed cell lines such as MDAY-D2 tumor cells is a specific measure of inhibition of oligosaccharide processing. The measurement of IC 50 in the L-PHA toxicity assay reflects the ability of the compound to enter into cells and to effect inhibition of oligosaccharide processing. It is a general screen for activity in cells which measures cell entry, inhibition of the target enzyme, α- mannosidase II in the Golgi, and the resulting cellular phenotype. Therefore, a compound of the invention may be tested for its ability to inhibit N-linked oligosaccharide processing by growing transformed cells in the presence of L-PHA and the compound; measuring the amount of proliferation of the cells; and determining the ability of the compound to inhibit N-linked oligosaccharide processing by comparing the amount of proliferation of the cells with the amount of proliferation observed for the cells grown in the presence of L-PHA alone. Transformed cells which may be used in this assay include MDAY-D2, L1210, CHO, B16, melanoma tumor cells, and human tumor cells such as SW 480, LS174T, HT-29, WiDr, T2, MDA-231, MCF7, BT- 20, Hs578T, K562, Hs578T, SK-BR-3, CY 6T, MDA-468, H23, H157, H358, H1334, HI 155, H28, H460, Hmesol, H187, H510A, N417, H146, H1092, H82 (Restifo, N. P. et al, J. Exper. Med. 177:265- 272, 1993). The amount of proliferation of the cells may be measured using conventional techniques. For example, cell proliferation may be measured by measuring incorporation of labeled thymidine. More particularly, radioactively labeled thymidine may be added for about 2-5 hours, preferably 3-4 hours and the cells can be harvested and radioactivity counted using a scintillation counter. The conditions for carrying out the above assay will be selected having regard to the nature of the compound and the cells employed. For example, if the transformed cells are MDAY-D2 tumor cells a concentration of about 1-4 x 10 4 cells, preferably 2 x 10" may be used. The MDAY-D2 cells are generally cultured for about 10 to 30 hours, preferably 18 to 20 hours, followed by addition of L-PHA at a concentration of about 10-50 μg/ml preferably 20-30 μ/ml, most preferably 25 μg/ml. The following L-PHA assay may be used to assay for inhibition of oligosaccharide processing (ie. Golgi α-mannosidase II) in viable cells. MDAY-D2 tumor cells are inoculated into 96 well micro-test plates at 2 x 10 4 cells/well, containing serial dilutions of the compound to be tested in MEM plus 10% FCS. The cells are cultured for 18-20 hours, followed by the addition of L-PHA at 25 μg/ml for an additional 24 hours. Cell proliferation is measured by adding 0.5 μCi/well of 3 H-thymidine for 3-4 hours, harvesting onto glass fibre disks using a Titertek harvester, and counting the disks in a liquid scintillation counter. The apparent IC 50 values for the test compounds are the drug concentrations showing 50% protection from L-PHA toxicity; that is 50% 3 H-thymidine incorporated compared with cells grown in the absence of L-PHA. The ability of the compounds of the formulae I in which the free hydroxyls have been esterified, to be converted into more active compounds in cells can be measured by performing the L-PHA toxicity assay in the presence of an esterase inhibitor such as diethyl p-nitrophenyl phosphate. For example, the esterase inhibitor diethyl p-nitrophenyl phosphate can be added to MDAY-D2 cells in the above described assay method about 4 hours prior to the α-mannosidase inhibitors. An increase in IC 50 in the L-PHA toxicity assay in the presence of diethyl p-nitrophenyl phosphate indicates that the compound requires activation by esterases and would accordingly be useful as a prodrug. This method may be used to screen for prodrugs and can be used to identify substances which inhibit all steps in the N-linked oligosaccharide pathway prior to β 1 -4 Gal-transferase. The compounds of the formula I have valuable pharmacological properties and they provide immunostimulatory, antimicrobial and anti-cancer effects. In particular, the compounds are useful in the prevention, treatment and prophylaxis of tumor growth and metastasis of tumors. The anti-metastatic effects of the compounds of the invention may be demonstrated using a lung colonization assay. For example, melanoma cells treated with a compound may be injected into mice and the ability of the melanoma cells to colonize the lungs of the mice may be examined by counting tumor nodules on the lung after death. Suppression of tumor growth in mice by the compound administered orally or intravenously may be examined by measuring tumor volume. The compounds of the formula I has particular application in the prevention of tumor recurrence after surgery i.e. as an adjuvant therapy. The compounds of the invention may be especially useful in the treatment of various forms of neoplasia such as leukemias, lymphomas, melanomas, adenomas, sarcomas, and carcinomas of solid tissues in patients. In particular the composition may be useful for treating malignant melanoma, pancreatic cancer, cervico-uterine cancer, cancer of the kidney, stomach, lung, rectum, breast, bowel, gastric, liver, thyroid, neck, cervix, salivary gland, leg, tongue, lip, bile duct, pelvis, mediastinum, urethra, bronchogenic, bladder, esophagus and colon, and Kaposi's Sarcoma which is a form of cancer associated with HIV-infected patients with Acquired Immune Deficiency Syndrome (AIDS). The compounds may also be used for other anti- proliferative conditions such as arthrosclerosis and viral infections, in particular AIDS. The compounds of the formula I may be used to stimulate bone marrow cell proliferation (hemorestoration), in particular following chemotherapy or radiotherapy. The myeloproliferative activity of a compound of the formula I may be determined by injecting the compound into mice, sacrificing the mice, removing bone marrow cells and measuring the ability of the compound to stimulate bone marrow proliferation by directly counting bone marrow cells and by measuring clonogenic progenitor cells in methylcellulose assays. The compounds of the invention are immune modulators and in particular they have immunostimulatory properties. Therefore, the compounds of the formula I may be used in cases where a patient has been immunocompromised such as patients infected with HIV, or other viruses or infectious agents including bacteria and fungi, in patients undergoing bone marrow transplants, and in patients with chemical or tumor- induced immune suppression. The compounds also have an antiviral effect in particular on membrane enveloped viruses such as retroviruses, influenza viruses, cytomegaloviruses and herpes viruses. The compounds of the invention may also be used in the treatment of inflammation. The term "patient" refers to a warm-blooded animal such as a mammal which is afflicted with a particular disease state or condition as described herein. Examples of animals within the scope of the meaning of the term are dogs, cats, rats, mice, horses, bovine cattle, sheep, and humans. The compounds may be converted using customary methods into pharmaceutical compositions. The pharmaceutical compositions contain the compounds either alone or together with other active substances. Such pharmaceutical compositions can be for oral, topical, rectal, parenteral, local, inhalant, or intracerebral use. They are therefore in solid or semisolid form, for example pills, tablets, creams, gelatin capsules, capsules, suppositories, soft gelatin capsules, liposomes (see for example, U.S. Patent Serial No. 5,376,452), gels, membranes, and tubelets. For parenteral and intracerebral uses, those forms for intramuscular or subcutaneous administration can be used, or forms for infusion or intravenous or intracerebral injection can be used, and can therefore be prepared as solutions of the compounds or as powders of the active compounds to be mixed with one or more pharmaceutically acceptable excipients or diluents, suitable for the aforesaid uses and with an osmolarity which is compatible with the physiological fluids. For local use, those preparations in the form of creams or ointments for topical use or in the form of sprays should be considered; for inhalant uses, preparations in the form of sprays, for example nose sprays, should be considered. The pharmaceutical compositions can be prepared by per se known methods for the preparation of pharmaceutically acceptable compositions which can be administered to patients, and such that an effective quantity of the active substance is combined in a mixture with a pharmaceutically acceptable vehicle. Suitable vehicles are described, for example, in Remington's Pharmaceutical Sciences (Remington's Pharmaceutical Sciences, Mack Publishing Company, Easton, Pa., USA 1985). On this basis, the pharmaceutical compositions include, albeit not exclusively, the compounds in association with one or more pharmaceutically acceptable vehicles or diluents, and contained in buffered solutions with a suitable pH and iso-osmotic with the physiological fluids. The compounds are indicated as therapeutic agents either alone or in conjunction with other therapeutic agents or other forms of treatment (e.g. chemotherapy or radiotherapy). For example, the compounds may be used in combination with anti-proliferative agents, antimicrobial agents, immunostimulatory agents, or anti-inflammatories. In particular, the compounds may be used in combination with anti-viral and/or anti- proliferative agents such as interferons. The compounds of the invention may be administered concurrently, separately, or sequentially with other therapeutic agents or therapies. In general, a dosage range of the compounds in the composition is envisaged for administration in human medicine of from about 0.001 to 50 mg/kg of body weight daily. In the case of intravenous compositions, the dosage is for example about .1 to 0.6 mg/kg/day, and for oral compositions the dosage is about 0.5 to 6 mg/kg/day. Amounts of drug administered to produce serum levels 10-lOOOx the IC 50 for inhibition of oligosaccharide processing in the L-PHA assay are preferably employed. It will also be appreciated that it may be necessary to deviate from the amounts mentioned and in particular to do so as a function of the body weight of the animal to be treated, the particular disease to be treated, the nature of the administration route and the therapy desired. In addition, the type of animal and its individual behaviour towards the medicine or the nature of its formulation and the time or interval at which it is administered may also indicate use of amounts different from those mentioned. Thus it may suffice, in some cases, to manage with less than the above-mentioned minimum amounts whilst in other cases the upper limit mentioned must be exceeded. Where major amounts are administered, it may be advisable to divide these into several administrations over the course of the day. The following non-limiting examples are illustrative of the present invention: Examples Example 1 Process for the Preparation of ( lS,2R,6S,8R,8aR)-6-Ethyl-l,2,8 trihydroxyindolizidine [(6S)-6-Ethylswainsonine] (275) 248 Methyl (E)-(2S,6S,7R)-2-Ethyl-8-hydroxy-6,7-0-isopropyIidenedioxy-4-octenoate and Methyl (E)-(2R,6S,7R)-2-Ethyl-8-hydroxy-6,7-0-isopropyIidenedioxy-4-octenoate (261α/β). Trimethyl orthobutyrate (8.5 mL, 7.9 g, 53 mmol) and propionic acid (39 mg, 0.53 mmol) were added to the neat allylic alcohol 248 ' (1.60 g, 5.31 mmol). The flask was fitted with a distillation head and was heated in an oil bath (125°C), distilling off methanol as it formed. After 24 h, the mixture was cooled to room temperature and concentrated. The crude residue was dissolved in THF (25 mL), cooled to 0°C, and tetra-n-butylammonium fluoride (5.9 mL of a 1 M soln. in THF, 5.9 mmol) was added in a dropwise fashion. After 2 h, the solution was diluted with ether (100 mL) and washed with brine (2 x 50 mL). The aqueous layers were back-extracted with EtOAc (100 mL), then the combined organic layers were dried (MgS0 4 ), and concentrated. Chromatography (3:1 hex/EtOAc) provided 1.20 g (83%) of an inseparable mixture (1:1) of diastereomeric alcohols 261α/β as a pale yellow oil. Characterization was performed on the mixture. R f = 0.27 (2: 1 hex/EtOAc); Η NMR (CDC1 3 , 360 MHz) δ 5.74 (m, IH), 5.54 (dd, J = 7.8, 16.4 Hz, IH), 4.61 (dt, J = 4.3, 7.1 Hz, IH), 4.21 (ddd, J = 1.3, 5.7, 12.5 Hz, IH), 3.68 (s, 3H), 3.55 (m, 2H), 2.4 (m, 2H), 2.28 (m, IH), 2.04 (m, IH), 1.5-1.7 (m, 2H), 1.49 (s, 3H), 1.37 (s, 3H), 0.90 (t, J = 7.4 Hz, 3H); 13C NMR (CDC1 3 , 90 MHz) δ 175.9, 175.9, 132.7, 132.3, 127.1, 126.9, 108.6, 78.3, 78.2, 77.9, 77.8, 61.9, 51.5, 46.7, 46.6, 34.4, 34.2, 27.8, 25.2, 25.1, 24.8, 11.6; IR (neat) 3483 ( , br), 2936 (m), 1737 (s) cm 1 ; MS (CI, NH 3 ) m/z (rel intensity) 290 [(M + NH 4 )+, 6], 215 (100), 202 (43), 185 (23); HRMS (CI, NH 3 ) calcd for C 14 H 24 0 5 NH 4 [(M + NH 4 )+] 290.1967, found 290.1973. Methyl (E)-(2S,6S,7R)-8-Azido-2-ethyl-6,7-0-isopropylidenedioxy-4-octenoate and Methyl (E)-(2R,6S,7R)-8-Azido-2-ethyl-6,7-0-isopropyIidenedioxy-4-octenoate (263α/β). Hydrazoic acid (9 6 mL of a 1 2 M solution in benzene 1 1 5 mmol) was added to a solution of the alcohol 261α/β (1 56 g, 5 73 mmol) and tπphenylphosphtne (2 25 g 8 59 mmol) in benzene (29 mL) The mixture was cooled to 5°C and diethyl azodicarboxylate (1 41 mL, 8 59 mmol) was added in a dropwise fashion The solution was then allowed to warm to room temperature 1 5 h TLC indicated that starting mateπal was still present More hydrazoic acid solution (4 9 mL, 5 7 mmol) tπphenvlphosphtne (0 75 g, 2 87 mmol), and DEAD (047 mL, 2 87 mmol) were added and the mixture was allowed to stir at room temperature for another 1 h The mixture was then poured into hexanes (80 mL) resulting in the formauon of a white precipitate The mixture was filtered and the filtrate was concentrated Chromatography (15 1 to 10 1 hexane/EtOAc) provided 1 50 g (85%) of an inseparable mixture (1 1 ) of diastereomeπc azides 263α/β as a colorless oil Characteπzation was performed on the mixture R, = 0 42 (5 1 hex EtOAc), 'H NMR (CDC1„ 300 MHz) δ 5 75 (m, IH), 5 49 (m, IH), 4 60 (m.lH) 4 25 (td, J = 4 3, 7 0 Hz, IH), 3 67 (s, 3H), 3 26 (dd, J = 7 7, 12 8 Hz, IH), 3 15 (dd, J = 4 3, 12 8 Hz, IH). 2 39 (m. 2H), 2 26 (m, IH), 1 5-1 7 (m, 2H), 1 51 (s, 3H), 1 37 (s, 3H), 0 90 (t, J = 7 4 Hz, 3H) π C NMR (CDC13, 75 MHz) δ 175 5, 132 9, 132 7, 126 5, 126 3, 109 0, 77 9, 77 8, 76 9, 51 6, 51 4, 46 7 46 6, 34 4, 34 3, 27 8, 25 3, 25 1, 24 9, 11 6, IR (neat) 2937 (m), 2102 (s), 1736 (s) cm ', MS (CI, NH,) m z (rel intensity) 315 [(M + NH 4 )+, 16], 270 (79), 240 (100), 212 (18), HRMS (CI, NH 3 ) calcd for C 14 H 23 N 3 0 4 NH 4 [(M + NH 4 )+] 315 2032, found 315 2042 Methyl (2S,4R,5S,6R,7R)-8-Azido-4,5-epoxy-2-ethyl-6,7-0-isopropylidenedi oxyoctanoate [(2S)-265α], Methyl (2R,4R,5S,6R,7R)-8-Azido-4,5-epoxy-2-ethyl-6,7- O-isopropylidenedioxyoctanoate f(2R)-265α], Methyl (2S,4S,5R,6R,7R )-8-Azido-4,5- epoxy-2-ethyl-6,7-0-isopropy!idenedioxyoctanoate [(2S)-265β], and Methyl (2R,4S,5R,6R,7R)-8-Azido-4,5-epoxy-2-ethyl-6,7-0-isopropyIidenedιoxyoctanoate f(2R)-265β]. (2S)-265α (2Λ)-265α (2RS)-265,9 m-Chloroperbenzoic acid (2 65 g, technical grade, 2 12 g pure, 12 3 mmol) was added to a cooled (0°C) solution of the azide (263α/β) (1 46 g, 4 91 mmol) in CH,CK (25 mL) After 24 h the mixture was diluted with ether (100 mL) and washed with 1 M NaOH (2 x 50 mL) The aqueous lavers were back extracted with ether (2 x 50 mL) and the combined organic layers were washed with saturated NaHCO ( 100 mL) and bπne (50 mL), then dried (MgS0 4 ), filtered, and concentrated ( 15 1 to 10 1 hex/EtOAc gradient) provided 0 54 g (35%) of the epoxide isomer (2R)-265α as a pale vellov. oil followed by 0 52 g (34%) of the epoxide isomer (2S)-265α as a pale yellow oil. followed b> 0 28 g ( 18%) of an inseparable mixture (1 1) of diastereomeπc epoxides (2RS)-265β Data for (2S)-265α R f = 0 52 (3 1 hex/EtOAc), [α] 2, D = +64 4° (c 0 80, CHC1,), 'H NMR (CDC1, 300 MHz) 6 4 35 (td, J = 4 2, 6 8 Hz, IH), 3 71 (s, 3H), 3 69 (dd, J = 64, 7 9 Hz. IH) 3 58 (dd J = 4 2 13 0 Hz, IH), 3 51 (dd, J = 7 0, 13 0 Hz, IH), 2 87 (ddd, J = 2 0, 4 6, 6 8 Hz, IH), 2 80 (dd. J = 2 0 8 0 Hz, IH), 2 52 (m, IH). 2 02 (ddd, J = 4 6, 9 8, 14 2 Hz, IH), 1 55-1 75 (m, 3H). 1 52 (s 3H) 1 36 (2, 3H), 0 91 (t, J = 7 5 Hz, 3H), 13 C NMR (CDC1„ 75 MHz) δ 175 4, 109 9, 77 4 76 7. 56 6 55 3 51 6. 50 6, 44 1, 33 6, 27 6, 25 7, 25 1 , 1 1 6, IR (neat) 2967 (m), 2102 (s), 1735 (s) cm-1. MS (CI, NH,) m z (rel intensity) 331 [(M + NH 4 )+, 22], 314 (47), 286 (100), 254 (53), 228 (30), 142 (44) HRMS (CI. NH,) calcd for C 14 H 23 N 3 0 5 NH 4 [(M + NH 4 )+] 331 1981, found 331 1975 Data for (2R)-265α R f = 0 45 (3 1 hex EtOAc), [α]23D = +50 6° (c 0 87, CHC1,), 'H NMR (CDC1 3 , 300 MHz) δ 4 35 (td, J = 4 2, 6 8 Hz, IH), 3 71 (s, 3H), 3 70 (m, IH), 3 58 (dd, J = 4 2, 13 1 Hz, IH), 3 52 (dd, J = 6 9, 13 0 Hz, IH), 2 91 (td, J = 2 0, 5 8 Hz, IH), 2 77 (dd J = 2 0, 7 9 Hz, IH), 2 50 (m, IH), 1 82 (m, 2H), 1 55-1 75 (m, 2H), 1 52 (s, 3H), 1 36 (s, 3H), 0 91 (t. J = 7 4 Hz, 3H), "C NMR (CDCl j , 75 MHz) δ 175 6, 109 9, 77 4, 76 7, 56 2, 55 1, 51 7, 50 5, 44 2, 33 4 27 5, 25 0, 24 9, 11 5, IR (neat) 2937 (m), 2102 (s), 1736 (s) cm-1 , MS (CI, NH 3 ) m/z (rel intensity) 331 [(M + NH 4 )+, 24], 314 (43), 286 (100), 254 (33), 228 (26), 178 (24), 142 (31), HRMS (CI, NH,) calcd for C 14 H 23 N 3 0 5 NH 4 [(M + NH 4 )+] 331 1981, found 331 1995 Data for (2RS)-265β (characteπzation was performed on the mixture) R r = 0 38 (3 1 hex/EtOAc), Η NMR (CDC1 3 , 300 MHz) δ 4 33 (td, J = 5 4, 6 7 Hz, IH), 3 98 (td, J = 5 2, 6 7 Hz, IH), 3 71 (s, 3H), 3 5 (m, 2H), 2 75-2 95 (m, 2H), 2 4-2 6 (m, IH), 2 05 (m, 0 5 H), 1 5-1 9 (m, 3 5 H), 1 49 (s, 3H), 1 34 (s, 3H), 0 91 (m, 3H), 13 C NMR (CDC1 3 , 75 MHz) δ 175 5, 109 7, 76 6, 76 0, 75 9, 56 0, 55 8, 53 2, 52 9, 51 7, 51 6, 51 1, 51 0, 44 0, 33 6, 33 4, 27 3, 25 8, 25 3, 25.2, 1 1 6, 1 1 5, IR (neat) 2938 (m), 2103 (s), 1738 (s), 1455 (m), 1372 (m) cm ', MS (CI, NH 3 ) m z (rel intensity) 331 [(M + NH 4 )+, 22], 314 (36), 286 (100), 254 (42), 142 (27),, HRMS (CI, NH 3 ) calcd for C ]4 H 23 N 3 0 5 NH 4 [(M + NH 4 )+] 331 1981, found 331.1981 (lS,2R,6S,8R,8aR)-6-Ethyl-8-hydroxy-l,2-0-isopropyIidene-dioxyindolizidin-5-one 98/14445 15 (267 ). Palladium hydroxide on carbon (70 mg) was added to a solution of the epoxide (2S )-265α (520 mg, 1 65 mmol) in MeOH/EtOAc (1: 1, 25 mL) The flask was evacuated (aspirator) and purged with hydrogen three times, and the resulung heterogeneous mixture was stirred under a balloon of hydrogen After 3 h, the hydrogen was evacuated, the mixture was filtered, and the filtrate was concentrated The residue was redissolved in MeOH (40 mL), sodium methoxide (20 mg, 0.37 mmol) was added, and the mixture was warmed to reflux Reaction progress was monitored by IR for the disappearance of the ester and lactone carbonyl stretches at 1730 cm ' and 1780 cm ' and appearance of the lactam carbonyl stretch at 1625 cm ' After 36 h, the mixture was cooled to room temperature and concentrated The residue was dissolved in CH 2 CI 2 /MeOH (20.1, 10 mL), Flonsil (500 mg) was added, and the mixture was stirred for 15 min The suspension was then filtered through Cehte and the filtrate was concentrated Chromatography (50 1 CH 2 Cl 2 /MeOH) provided 280 mg (66%) of the lactam 267 as a white crystalline solid The C(6) stereochemical assignment was based on analysis of IH NMR coupling constants and the results of the reductive double cyclization of (2R)-265α- (see below). R r = 0.30 (20: 1 CHCl,/MeOH), [α] 23 D = +6 7° (c 0.38, CHC1 3 ); mp 162 °C; 'H NMR (CDC1„ 360 MHz) δ 4.81 (dd, J = 4 6, 6.0 Hz, I H, H,), 4 75 (ddd, J = 1, 5.0, 6.0 Hz, IH, H 2 ), 4.21 (d, J = 13.7 Hz, IH, H 3cq ), 4.15 (dddd, J = 4.0, 4.6, 8.8, 12.8 Hz, IH, H 8 ), 3.34 (dd, J = 4.4, 8.6 Hz, IH, H 8a ), 3 14 (dd, J = 5.1, 13.7 Hz, IH, H 3 .„), 2.84 (d, J = 4.6 Hz, IH, H 8 . 0 „), 2.33 (m, IH, H 6 ), 2.22 (ddd, J = 3.9, 6.0, 12.4 Hz, IH, H 7cq ), 1.99 (m, IH, H 9 ), 1.64 (app q, J = 12.2 Hz, IH, H 7ax ), 1.55 (m, IH, H 9 ), 1.42 (s, 3H), 1.34 (s, 3H), 0.93 (t, J = 7.5 Hz, 3H, H,„), 13 C NMR (CDC1 3 , 90 MHz) δ 170.7, 112.1, 79.8, 77.7, 66.3, 65.1, 50.6, 40.9, 35.1 , 26.3, 24.7, 24.5, 1 1.1 ; IR (neat) 3310 (m), 2956 (m), 2874 (m), 1609 (s) cm 1 ; MS (El, 70eV) m z (rel intensity) 255 (M+, 22), 240 (22), 227 (100), 180 (21), 142 (13), 113 (35), 1 10 (21), 84 (50), 68 (1 1 ), HRMS (El, 70eV) calcd for C 13 H 2l N0 4 (M+) 255.1471, found 255.1463. (lS,2R,6R,8R,8aR)-6-Ethyl-8-hydroxy-l,2-0-isopropylidenedioxyindolizidin-5-one (269) The reductive double cyclization of (2R)-265α (515 mg, 1.63 mmol) was earned out according to the procedure descπbed above for (2S)-265α Chromatography (100: 1 CH,Cl : /MeOH) provided 85 mg (20%) of the lactam 267 (see above for charactenzation) followed by 171 mg (41 %) of lactam 269 Formation of 267 indicated that epimeπzation at C(6) was taking place under the reaction conditions suggesting that the ethyl substituent in 267 most likely occupied an equatonal position and that the ethyl substituent in 269 occupied an axial position. Analysis of the 'H NMR coupling constants in 267 and 269 confirmed this assignment R f = 0.25 (20:1 CHCl,/MeOH), [α] 2, D = -13.2° (c 0 38, CHC1,), 'H NMR (CDC1 3 , 300 MHz) δ 4.80 (dd, J = 4.3, 6.0 Hz, IH, H,), 4.73 (dd, J = 5.0, 6.0 Hz, I H. H 2 ). 4.27 (ddd, J = 4.3, 7.8, 10.5 Hz, IH, H 8 ), 4.15 (d, J = 13.5 Hz, IH, H 3cq ), 3.30 (dd, J = 4.2, 7 6 Hz. IH, H , 3.09 (dd, J = 4.8, 13.6 Hz, IH, H 3 ..), 3.00 (br s, IH, H 8 0H ), 2 41 (m. IH, H«), 2.06 (dt, J = 3.9, 13.2 Hz, IH), 1.90 (m, 2H), 1.55 (m, IH), 1.40 (s, 3H), 1.33 (s, 3H), 1.01 (t, J = 7 4 Hz, 3H) , 13C NMR (CDC1 3 , 75 MHz) δ 171.8, 111.8, 79.7, 77.6, 66.6, 62.3, 50.5, 41.0, 33.4, 26 4, 25.6, 24.7, 12.2, IR (neat) 3380 (br m), 2936 (m), 2874 (m), 1622 (s) cm-1 ; MS (El, 70 eV) m/z (rel intensity) 255 (M+, 18), 240 (22), 227 (100), 180 (28), 113 (34), 84 (41), HRMS (El, 70eV) calcd for C„H 21 N0 4 (M+) 255.1471 , found 255.1465. (lS,2R,6S,8R,8aR)-6-Ethyl-8-hydroxy-l,2-0-isopropyIidene-dioxy-indolizidine (271 ) Reduction of the lactam 267 (265 mg, 1.04 mmol) was earned out with borane-methyl sulfide complex 2 Chromatography (50:1 CH 2 Cl 2 /MeOH) provided 241 mg (96%) of the indolizidine 271 as a white crystalline solid. R r = 0.24 (20:1 CHCl 3 /MeOH); [α] 23 D = -52.0° (c 1.31, CHC1 3 ); mp 95 °C; Η NMR (CDC1 3 , 360 MHz) δ 4.69 (dd, J = 4.6, 6.2 Hz, IH, H,), 4.62 (dd, J = 4.2, 6.2 Hz, IH, H 2 ), 3.87 (m, IH, H 8 ), 3.14 (d, J = 10.7 Hz, IH, H 3eq ), 3.04 (dd, J = 3.9, 10.4 Hz, IH, H^), 2.11 (m, 3H, H 3ax +H 7κ) +H 8 . OH ), 98/14445 - 17 - 1.68 (m, IH, H 6 ), 1.62 (dd, J = 4.4, 9.0 Hz, IH. H s .). 1.54 (d. J = 10.5 Hz. IH. H 5a „). 1.50 (s. .3H). 1.34 (s, 3H), 1.27 (quint, J = 7.4 Hz, 2H, H 9 ), 0.95 (t. J = 12.0 Hz. IH. H 7 „). 0.90 (t. J = 7.4 Hz. 3H. H, 0 ): ,3 C NMR (CDC1 3 , 90 MHz) δ 11 1.3, 78.9, 78.5, 73.7, 67.1 , 59.7, 57.3, 39.7. 36.9, 26.7. 26.0, 24.8. 11.6; IR (neat) 3250 (br m), 2962 (s), 2803 (m) cm '; MS (El, 70eV) m/z (rel intensity) 241 (M+, 56). 166 (100), 156 (29), 141 (59), 124 (40), 98 (32); HRMS (El, 70eV) calcd for C,,H,,NO, (M+) 241.1678. found 241.1672. 273 (lS,2R,6R,8R,8aR)-6-Ethyl-8-hydroxy-l,2-0-isopropylidene-dioxy-indoIizidine (273) Reduction of the lactam 269 (150 mg, 0.59 mmol) was carried out with borane-methyl sulfide complex. Chromatography (100:1 to 50:1 CH 2 Cl 2 /Me0H gradient) provided 145 mg (100%) of the indolizidine 273 as a colorless oil that crystallized upon standing. R f = 0.27 (20: 1 CHCl,/MeOH); [α] :, D = -27.9° (c 1.17, CHC1 3 ); mp 73-75 °C; 'H NMR (CDC1 3 , 300 MHz) δ 4.69 (dd, J = 4.2, 6.3 Hz, IH, H,), 4.61 (dd, J = 4.3, 6.3 Hz, IH, H 2 ), 3.97 (ddd, J = 4.6, 9.0, 11.5 Hz, IH, H„), 3.06 (d, J = 10.6 Hz, IH, H 3c ), 2.85 (d, J = 10.9 Hz, IH, H 5eq ), 2.51 (br s, IH, H 8 . OH ) 2.07 (dd, J = 4.3, 10.6 Hz, IH, H 3 „), 2.00 (m, 2H, H 5a χ+H 7eq , 1.65 (m, IH, H6), 1.5-1.6 (m, 2H, H8a+H9), 1.49 (s, 3H), 1.3-1.5 (m, 2H, H t H 7ax ), 1.34 (s, 3H), 0.89 (t, J = 7.3 Hz, 3H, H 10 ); 13 C NMR (CDC1 3 , 75 MHz) δ 11 1.5, 79.5, 78.5, 74.3, 64.0, 60.5, 54.7, 37.1, 36.8, 26.3, 25.6, 25.4, 12.7; IR (neat) 3420 (br m), 2934 (s), 2784 ( ), 1462 (m) cm '; MS (El, 70eV) m/z (rel intensity) 241 (M+, 47), 166 (100), 156 (36), 141 (65), 124 (52), 98 (39), 55 (44); HRMS (El, 70eV) calcd for C 13 H 23 N0 3 (M+) 241.1678, found 241.1688. (lS,2R,6S,8R,8aR)-6-Ethyl-l,2,8-trihydroxyindolizidine [(6S)-6-Ethyl-swainsonine] (275) The acetonide of the indolizidine 271 (200 mg, 0.83 mmol) was hydrolyzed with 6 N HC1 in THF. Chromatography (50:10:1 CH 2 Cl 2 /MeOH/Aq. NH 4 OH) provided 166 mg (99%) of the title compound as a white solid that was recrystallized from n-butanol. R f = 0.42 (2:1 CHCl 3 /MeOH); [α] 23 D = -42.3° (c 1.17, CHC1 3 ); mp 134 °C; Η NMR (CD 3 OD, 360 MHz) δ 4.19 (m, 2H), 3.79 (td, J = 4.5, 10.5 Hz, IH), 2.9 (m, 2H), 2.38 (dd, J = 7.2, 10.3 Hz, IH), 2.03 (m, IH), 1.67 (dd, J = 3.2, 8.7 Hz, IH), 1.5 (m, 2H), 1.25 (m, 2H), 0.90 (t, J = 7.4 Hz, IH); 13C NMR (CD 3 OD, 90 MHz) δ 75.3, 70.6, 70.2, 66.9, 63.1, 59.0, 41.0, 37.7, 28.0, 12.0; IR (neat) 3375 (br s), 2944 (s), 2793 (m), 1614 (w) cm " '; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 202 [(M + H)+, 91), 184 (100), 141 (10); HRMS (CI, CH 4 and NH 3 ) calcd for C 10 H 19 NO 3 H [(M + H)+] 202.1443, found 202.1444. Anal. Calcd for C 10 H 19 NO 3 : C, 59.68; H, 9.52; N, 6.96. Found C, 59.69; H, 9.67; N, 6.96. Example 2 Process for the Preparation of (lS,2R,6R,8R,8aR)-6-Ethyl- l,2,8- trihydroxyindolizidine [(6R)-6-Ethyl-swainsonine] (277) 277 The acetonide of the indolizidine 273 (105 mg, 0.44 mmol) was hydrolyzed with 6 N HC1 in THF. Chromatography (50:10:1 CH 2 Cl 2 /MeOH/Aq. NH 4 OH) provided 84 mg (96%) of the title compound as a colorless oil. R f = 0.55 (2: 1 CHCl 3 /MeOH); [α] 23 D = -39.0° (c 1.17, CHC1 3 ); Η NMR (D 2 0, 300 MHz) δ 4.34 (td, J = 2.5, 7.7 Hz, IH), 4.23 (dd J = 3.6, 5.9 Hz, IH), 3.96 (ddd, J = 4.5, 9.6, 11.1 Hz, IH), 2.88 (m, 2H), 2.51 (dd, J = 8.0, 11.0 Hz, IH), 2.09 (dd, J = 3.8, 11.5 Hz, IH), 2.02 (m, IH), 1.86 (dd, J = 3.5, 9.4 Hz, IH), 1.75 (m, IH), 1.35-1.50 (m, 3H), 0.90 (t, J = 7.4 Hz, 3H); 13 C NMR (CD 3 OD, 90 MHz) δ 76.0, 71.4, 70.4, 64.2, 63.5, 56.7, 38.2, 38.0, 26.4, 13.1 ; IR (neat) 3355 (br s), 2929 (s), 2784 (m), 1460 (m) cm " '; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 202 [(M + H)+, 70), 184 (100), 166 (10), 141 (11); HRMS (CI, CH 4 and NH 3 ) calcd for C 10 H 19 NO 3 H [(M + H)+] 202.1443, found 202.1438. Example 3 Process for the Preparation of (lS,2R,6S,8R,8aR)-6-[2-(Benzyloxy)ethyl]-l,2,8- trihydroxyindolizidine [(6S)-6-(2-BenzyloxyethyI) swainsonine] (276). 276 262α/β Methyl (E)-(2S,6S,7R)-2-[2-(Benzyloxy)ethyl]-8-hydroxy-6,7-0-isopropyIidenedioxy-4- octenoate and Methyl (E)-(2R,6S,7R)-2-[2-(Benzyloxy)ethyl]-8-hydroyx-6,7-0- isopropylidenedioxy-4-octenoate (262α/β) 4-Benzyloxy-l,l,l-trimethoxybutane (10.1 g, 60% pure by GC analysis, 24 mmol) and propionic acid (150 mg, 2.0 mmol) were added to a solution of the allylic alcohol 248 (3.54 g, 11.7 mmol) in toluene (40 mL). The flask was fitted with a distillation head and was warmed to reflux, distilling off methanol as it formed. After 24 h, the mixture was cooled to room temperature and concentrated. The crude residue was dissolved in THF (40 mL), cooled to 0 °C, and tetra-n- butylammonium fluoride (5.9 mL of a 1 M soln. in THF, 5.9 mmol) was added in a dropwise fashion. After 2 h, the solution was diluted with ether (100 mL) and washed with brine (2 x 50 mL). The aqueous layers were back-extracted with EtOAc (100 mL), then the combined organic layers were dried (MgS0 4 ), and concentrated. Chromatography (6: 1 to 2:1 hex/EtOAc gradient) provided 2.97 g (67%) of an inseparable mixture (1: 1) of diastereomeric hydroxy esters 262α/β as a pale yellow oil. R f = 0.19 (2: 1 hex EtOAc); IH NMR (CDC1 3 , 360 MHz) δ 7.2-7.4 (m, 5H), 5.73 (m, IH), 5.52 (dd, J = 8.0, 15.4 Hz, IH), 4.60 (m, IH), 4.48 (s, 2H), 4.20 (m, IH), 3.62 (m, 3H), 3.4-3.6 (m, 4H), 2.70 (m, IH), 2.2-2.5 (m, 3H), 1.96 (m, IH), 1.78 (m, IH), 1.49 (s, 3H), 1.38 (s, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 175.3, 138.4, 131.7, 131.5, 128.2, 127.5, 127.4, 108.5, 78.5, 78.0, 77.9, 73.0, 68.0, 61.9, 51.3, 42.4, 42.3, 34.8, 34.7, 31.9, 31.7, 27.8, 25.3; IR (neat) 3490 (br m), 2934 (m), 2868 (m), 1732 (s), 1441 (m) cm '; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 321 (12), 213 (28), 195 (48), 107 (28), 91 (100); HRMS (CI, CH 4 and NH 3 ) calcd for C 21 H 30 O 6 C 2 H 5 [(M + C 2 H 5 )+] 407.2434, found 407.2449. Anal. Calcd for C 2 ,H 30 O 6 : C, 66.65; H, 7.99. Found C, 66.33; H, 8.29. 264α/β Methyl (E)-(2S,6S,7R)-8-Azido-2-[2-(benzyloxy)ethyl]-6,7-0-isopropylidenedioxy -4- octenoate and Methyl (E)-(2R,6S,7R)-8-Azido-2-[2-(benzyloxy)ethyl]-6.7-0- isopropyIidenedioxy-4-octenoate (264α/β). Hydrazoic acid (12.3 mL of a 1.2 M solution in benzene, 14.8 mmol) was added to a solution of the alcohol 262α/β (2.81 g, 7.42 mmol) and tπphenylphosphme (2.91 g, 11.1 mmol) in benzene (29 mL). The mixture was cooled to 5 °C and diethyl azodicarboxylate (1.82 mL, 11.1 mmol) was added in a dropwise fashion. The solution was then allowed to warm to room temperature. After 1.5 h, TLC indicated that starting mateπal was still present More hydrazoic acid solution (6.2 mL, 7.5 mmol), tnphenylphosphme (0.97 g, 3.71 mmol). and DEAD (0.61 mL, 3.71 mmol) were added and the mixture was allowed to stir at room temperature for another 1 h The mixture was then poured into hexanes (100 mL), resulting in the formation of a white precipitate The mixture was filtered and the filtrate was concentrated. Chromatography (12: 1 to 6: 1 hexane/EtOAc gradient) provided 1.97 g (66%) of an inseparable mixture (1 : 1) of diastereomeπc azides 264o β as a colorless oil R f = 0.31 (5:1 hex/EtOAc); Η NMR (CDC1,, 300 MHz) δ 7.2-7.4 ( , 5H), 5.73 (m, IH), 5 46 (m, IH), 4.59 (t, J = 6.8 Hz, IH), 4.47 (s, 2H), 4.23 (ddd, J = 4.3, 6.7, 7.5 Hz, IH), 3.62 (d, J = 2.5 Hz. 3H), 3.46 (m, 2H), 3.24 (dd, J = 7.6, 12.8 Hz, IH), 3.13 (ddd, J = 1.4, 4.3, 12.8 Hz, IH), 2.68 (m, IH), 2.39 (m, IH), 2.30 (m, IH), 1.95 (m, IH), 1.77 (m, IH), 1.51 (s, 3H), 1.37 (s, 3H); ,3 C NMR (CDC1„ 75 MHz) δ 175.3, 138.2, 132.5, 132.3, 128.2, 127.5, 127.5, 126.8, 126.7 109.0, 77.8, 77.8, 76.9, 73.0, 67.9, 51.6, 51.5, 42.2, 42.1, 34.9, 34.8, 31.9, 31.7, 27.8, 25.3; IR (neat) 2988 (w), 2936 (w), 2862 (w), 2101 (s), 1732 (s) cm " '; MS (CI, NH 3 ) m z (rel intensity) 421 (24), 376 (100), 318 (35), 106 (29); HRMS (CI, NH 3 ) calcd for C 21 H 29 N 3 0 5 NH 4 [(M + NH 4 )+] 421.2451, found 421.2428. Anal. Calcd for C,,H 29 N,0,. C, 62.51 ; H, 7.24; N, 10.41. Found: C, 62.51 ; H, 7.23, N, 10.43. Methyl (2S,4R,5S,6R,7R)-8-Azido-2-[2-(benzyloxy)ethyl]-4,5-epoxy-6,7-0- isopropylidene-dioxyoctanoate [(2S)-266α], Methyl (2R,4R, 5S, 6R, 7R)-8-Azido-2- [2-(benzyIoxy)ethyl]-4,5-epoxy-6,7-0-isopropylidenedioxyoctanoate [(2R)-266α] , Methyl (2S,4S,5R,6R,7R)-8-Azido-2-[2-(benzyloxy)ethyI]-4,5-epoxy-6,7-0- isopropylidenedioxyoctanoate [(2S)-266β], and Methyl (2R,4S, 5R, 6R, 7R)-8-Azido- 2-[2-(benzyloxy)ethyI]-4,5-epoxy-6,7-0-isopropyIidenedioxyoctanoate [(2R)-266β]. m- Chloroperbenzoic acid (2.30 g, technical grade, 1.84 g pure, 12.3 mmol) was added to a cooled (0 ° solution of the azide 264α/β (1.72 g, 4.25 mmol) in CH 2 C1 2 (25 mL). After 24 h, the mixture was diluted with ether (100 mL) and washed with 1 M NaOH (2 x 50 mL). The aqueous layers were back- extracted with ether (2 x 50 mL) and the combined organic layers were washed with saturated NaHC0 3 (100 mL) and brine (50 mL), then dried (MgS0 4 ), filtered, and concentrated. Chromatography (15: 1 to 8: 1 hex/EtOAc gradient - 2 passes) provided 0.50 g (28%) of the epoxide isomer (2S)-266α as a pale yellow oil, followed by 0.50 g (28%) of the epoxide isomer (2R)-266α as a pale yellow oil, followed by 0.39 g (22%) of a mixture (1 :1) of diastereomeric epoxides (2RS)-266βα/β. Data for (2S)-266α: R f = 0.45 (6: 1 hex/EtOAc - 3 elutions); [α] 23 D = +39.8 (c 1.25, CHC1 3 ); Η NMR (CDC1 3 , 300 MHz) δ 7.2-7.4 (m, 5H), 4.47 (s, 2H), 4.33 (td, J = 4.1, 6.8 Hz, IH), 3.68 (dd, J = 6.5, 7.9 Hz, IH), 3.64 (s, 3H), 3.4-3.6 (m, 4H), 2.88 (ddd, J = 1.9, 4.9, 6.6 Hz, IH), 2.79 (m, 2H), 2.01 (m, 2H), 1.82 (m, IH), 1.67 (ddd, J = 5.0, 6.6, 14.2 Hz, IH), 1.51 (s, 3H), 1.34 (s, 3H); 13 C NMR (CDC1 3 , 75 MHz) δ 175.2, 138.2, 128.2, 127.5, 127.4, 109.8, 77.3, 76.6, 73.0, 67.7, 56.3, 55.2, 51.7, 50.5, 39.8, 34.0, 32.4, 27.6, 25.0; IR (neat) 2988 (w), 2936 (w), 2863 (w), 2102 (s), 1732 (s) cm '; MS (CI, NH 3 ) m/z (rel intensity) 437 [(M + NH 4 )+, 21], 392 (100), 360 (81), 224 (49), 142 (54), 131 (27), 108 (35); HRMS (CI, NH 3 ) calcd for C 21 H 29 N 3 0 6 NH 4 [(M + NH 4 )+] 437.2400, found 437.2379. Anal. Calcd for C 21 H 29 N 3 0 6 : C, 60.31; H, 6.97; N, 10.02. Found: C, 60.11; H, 6.98, N, 9.76. Data for (2R)-266α: R f = 0.38 (6: 1 hex/EtOAc - 3 elutions); [α] 23 D = +50.0° (c 0.80, CHC13); * H NMR (CDC1 3 , 360 MHz) δ 7.2-7.4 (m, 5H), 4.47 (s, 2H), 4.35 (dt, J = 4.0, 7.0 Hz, IH), 3.70 (dd, J = 6.5, 7.8 Hz, IH), 3.65 (s, 3H), 3.44-3.63 (m, 4H), 2.93 (ddd, J = 1.9, 4.6, 6.9 Hz, IH), 2.79 (m, 2H), 2.1 (m, IH), 1.75-1.95 (m, 3H), 1.51 (s, 3H), 1.35 (s, 3H); 13C NMR (CDC1 3 , 90 MHz) δ 175.5, 138.2, 128.3, 127.6, 127.6, 109.9, 77.3, 76.6, 73.0, 67.7, 56.1, 54.9, 51.8, 50.5, 39.9, 33.8, 31.7, 27.5, 25.0; IR (neat) 2988 (w), 2934 (w), 2862 (w), 2102 (s), 1732 (s) cm "1 ; MS (CI, NH 3 ) m/z (rel intensity) 437 [(M + NH 4 )+, 25], 420 (24), 392 (100), 360 (17), 142 (21); HRMS (CI, NH 3 ) calcd for C 21 H 29 N 3 0 6 NH 4 [(M + NH 4 )+] 437.2400, found 437.2410. Anal. Calcd for C 21 H 29 N 3 0 6 : C, 60.31; H, 6.97; N, 10.02. Found: C, 60.06; H, 6.91, N, 9.77. Data for (2RS)-266β: R f = 0.30 (6: 1 hex/EtOAc - 3 elutions); Η NMR (CDC1 3 , 360 MHz) δ 7.2- 7.4 (m, 5H), 4.47 (s, 2H), 4.31 (dd, J = 6.7, 12.0 Hz, IH), 3.96 (ddd, J = 4.9, 6.7, 11.1 Hz, IH), 3.65 (d, J = 3.7 Hz, 3H), 3.40-3.55 (m, 3H), 2.91 (m, IH), 2.80 (m, 2H), 2.02 (m, 1.5 H), 1.85 (m, 2H), 1.61 (m, 0.5 H), 1.51 (s, 3H), 1.35 (s, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 175.5, 138.2, 128.3, 127.7, 127.6, 109.8, 76.9, 76.4, 75.9, 75.8, 73.0, 67.6, 55.9, 55.7, 52.9, 52.7, 51.8, 51.7, 51.0, 50.9, 39.8, 39.7, 33.9, 33.8, 32.4, 31.8, 27.2, 27.1, 25.2; IR (neat) 2986 (w), 2936 (w), 2862 (w), 2102 (s), 1736 (s) cm " '; MS (CI, NH 3 ) m/z (rel intensity) 437 [(M + NH 4 )+, 24], 420 (22), 392 (100); HRMS (CI, NH 3 ) calcd for C 21 H 29 N 3 0 6 NH 4 [(M + NH 4 )+] 437.2400, found 437.2407. Anal. Calcd for C. 60.31 : H. 6.97; N, 10.02. Found: C, 60.29; H, 6.98, N, 9.97. (lS,2R,6S,8R,8aR)-6-[2-(Benzyloxy)ethyl]-8-hydroxy-l,2-0-isopropylidenedioxy- indolizidin-5-one (268). The reductive double cyclization of (2S)-265α (300 mg, 0.72 mmol) was carried out according to the general procedure described above for preparation of 222. Chromatography (100:1 to 50:1 CH 2 Cl 2 /MeOH) provided 204 mg (79%) of the lactam 268 as an oil. Data for 268: R ( = 0.15 (50:1 CHCl 3 /MeOH); [α] 23 D = -4.1° (c 1.03, CHC1 3 ); IH NMR (CDC1 3 , 360 MHz) δ 7.2-7.4 (m, 5H), 4.77 (dd, J = 4.6, 6.0 Hz, IH), 4.70 (t, J = 5.2 Hz, IH), 4.49 (ABq, J = 1 1.9 Hz, Dn = 17.5 Hz, 2H), 4.17 (d, J = 13.6 Hz, IH), 4.13 (m, IH), 3.60 (m, 2H), 3.28 (dd, J = 4.5, 8.8 Hz, IH), 3.07 (dd, J = 5.0, 13.6 Hz, IH), 2.74 (br s, IH), 2.54 (m, IH), 2.35 (m, IH), 2.22 (ddd, J = 3.9, 5.9, 12.5 Hz, IH), 1.6-1.8 (m, 2H), 1.41 (s, 3H), 1.32 (s, 3H); 13 C NMR (CDC1„ 90 MHz) δ 170.7, 138.4, 128.3, 127.6, 127.5, 112.0, 79.7, 77.6, 72.7, 67.9, 66.3, 64.9, 50.6, 37.0, 35.8, 31.3, 26.3, 24.6; IR (neat) 3380 (br w), 2934 (w), 2863 (w), 1621 (s), 1082 (s) cm '; MS (CI, NH 3 ) m/z (rel intensity) 362 [(M + H)+, 100], 270 (18), 227 (23); HRMS (CI, CH 4 and NH 3 ) calcd for C 20 H 27 NO 5 H [(M + H)+] 362.1967, found 362.1953. (lS,2R,6S,8R,8aR)-6-[2-(Benzyloxy)ethyI]-8-hydroxy-l,2-0-isopropyIidenedioxy- indolizidine (272). Reduction of the lactam 268 (120 mg, 0.33 mmol) was carried out with borane-methyl sulfide complex. Chromatography (25:25: 1 hex/EtOAc/EtOH) provided 108 mg (94%) of the indolizidine 272. R, = 0.20 (1:1 hex/EtOAc); [α] 23 D = -31.4° (c 0.87, CHC1 3 ); IH NMR (CDCl,, 300 MHz) δ 7.2-7.4 (m. 5H). 4.69 (dd, J = 4.5, 6.2 Hz, IH), 4.61 (dd, J = 4.1, 6.3 Hz, IH), 4.44 (s, 2H), 3.86 (m, IH), 3.49 (t. J = 6.6 Hz. 2H), 3.12 (d, J = 10.7 Hz, IH), 3.01 (dd, J = 3.9, 10.6 Hz, IH), 2.11 (m, 3H), 1.92 (m. IH). 1.58 (m, 4H), 1.50 (s, 3H), 1.33 (s, 3H), 0.98 (dt, J = 11.3, 12.0 Hz, IH); 1 C NMR (CDCl,, 90 MHz) δ 138.4. 128.3, 127.6, 127.5, 111.4, 78.9, 78.5, 73.5, 72.9, 68.2, 66.9, 59.6, 57.5, 39.9, 33.8. 32.6. 26.0, 24.8; IR (neat) 3450 (br m), 2931 (w), 2855 (m), 2786 (m), 1453 (m), 1369 (m) cm '; MS (CI. CH 4 and NH,) m/z (rel intensity) 348 [(M + H)+, 100], 270 (13), 256 (11); HRMS (CI, CH 4 and NH,) calcd for C 20 H 29 NO 4 H [(M + H)+] 348.2175, found 348.2168. Anal. Calcd for C 20 H 29 NO 4 : C, 69.14; H, 8.41 ; N, 4.03. Found, C, 68.97; H, 8.61 ; N, 4.02. (lS,2R,6S,8R,8aR)-6-[2-(Benzyloxy)ethyI]-l,2,8-trihydroxy-indoIizidine [(6R)-6-(2- Benzyloxyethyl)-swainsonine] (276). The acetonide of the indolizidine 272 (44 mg, 0.13 mmol) was hydrolyzed with 6 N HCl in THF. Chromatography (80:20:1 to 50:25:1 EtOAc/EtOH/Aq. NH 4 OH) provided 38 mg (97%) of the title compound (276) as a colorless oil. R r = 0.26 (2:1 EtOAc/EtOH); (α ] 23 D = -42.5° (c 0.89, MeOH); Η NMR (CD,OD, 300 MHz) δ 7.2-7.4 (m, 5H), 4.49 (s, 2H), 4.22 (ddd, J = 2.0, 6.2, 13.3 Hz, IH), 4.17 (dd, J = 3.6, 6.1 Hz, IH), 3.82 (ddd, J = 4.6, 9.3 11.1 Hz, IH), 3.53 (t, J = 6.4 Hz, 2H), 2.97 (dd, J = 3.2, 1 1.1 Hz, IH), 2.90 (dd, J = 1.9, 10.4 Hz, IH), 2.41 (dd, J = 7.0, 10.4 Hz, IH), 2.27 (m, IH), 1.87 (m, IH), 1.71 (dd, J = 3.5, 9.2 Hz, IH) 1.58 (m,3H), 0.93 (dt, J=l 1.3, 12.2 Hz, IH); 13 C NMR (CD 3 OD, 90 MHz) δ 140.0, 129.5, 129.0, 128.8, 75.2, 74.1, 70.6, 70.2, 69.2, 66.8, 63.0, 59.1, 41.3, 35.1, 33.3; IR (neat) 3780 (br s), 2941 (s), 2853 (m) cm-1 ; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 306 [(M- H)+, 3], 302 (3), 216 (100), 91 (40); HRMS (CI, CH 4 and NH 3 ) calcd for C 17 H 24 N0 4 [(M- H)+] 306.1705, found 306.1717. Example 4 Process for the Preparation of (lS,2R,7R,8R,8aR)-7-ButyI- l,2,8- trihydroxyindolizidine [(7R)-7-Butyl-swainsonine] (304). (2R,3S,4S)-l,4-Dihydroxy-2,3-0-isopropylidenedioxy-5-decyne (287). Addition of hexynylmagnesium bromide to 2,3-O-isopropylidene-D-erythrose has been reported by Mekki et al 2,3-0- Isopropylidene-D-erythrose was prepared via the diisobutylaluminum hydride reduction of 2,3-0- isopropylidene-D-erythronolactone (240) as described above for the synthesis of 248. Hexynylmagnesium chloride was prepared by adding isopropylmagnesium chloride (13.3 mL of a 2 M soln. in ether, 26.6 mmol) to a cooled (0°C) solution of 1-hexyne (3.0 mL, 2.15 g, 26.6 mmol) in THF (35 mL), and then allowing the solution to warm to room temperature. The hexynylmagnesium chloride solution was transferred via cannula into a cooled (-78°C) solution of 2,3-O-isopropylidene-D-erythrose (1.70 g, 10.6 mmol). The resulting mixture was stirred for 30 min at -78°C, and was then allowed to warm slowly to 0°C. After 6h, the reaction was quenched by addition of saturated aqueous NH 4 C1 (100 mL). The mixture was extracted with ether (2 x 100 mL), the combined organic phases were washed with water (50 mL) and brine (50 mL), and then dried (MgS0 4 ), and concentrated to provide 2.47 g of the diol 287 that was used without further purification. The stereochemistry of 287 was assigned based on the results of Mekki et al. A small sample was purified by chromatography (3:1 to 2: 1 hex/EtOAc gradient) to obtain an analytically pure sample. R f = 0.20 (2:1 hex/EtOAc); [α] 23 D = -10.6° (c 0.85, CHC1 3 ); IH NMR (CDC1 3 , 360 MHz) δ 4.60 (br s, IH), 4.32 (dt, J = 4.6, 6.0 Hz, IH), 4.21 (t, J = 6.4 Hz, IH), 3.94 (m, 2H), 3.76 (br s, IH), 3.19 (br s, IH), 2.23 (td, J = 2.0, 7.0 Hz, 2H), 1.35-1.55 (m, 4H), 1.49 (s, 3H), 1.38 (s, 3H), 0.91 (t, J = 7.3 Hz, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 108.6, 87.2, 79.2, 78.0, 77.1, 61.4, 60.4, 30.5, 27.3, 25.1, 21.9, 18.4, 13.5; IR (neat) 3380 (br, s), 1934 (s), 1380 (s) cm-1; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 243 [(M + H)+, 6], 225 (15), 185 (31), 167 (100), 125 (76); HRMS (CI, CH 4 and NH 3 ) calcd for C 13 H 22 0 4 H [(M + H)+] 243.1496, found 243.1596; Anal. Calcd for C 13 H 22 0 4 : C, 64.44; H, 9.15. Found: C, 64.12; H, 9.12.] (E)-(2R,3S,4S)-l-tert-Butyldimethylsilyloxy-4-hydroxy-2,3-0-isopropylidene dioxy-5- decene (289). Sodium bιs(2-methoxyethoxy)alumιnum hydπde (Red-Al) (6 0 mL of a 70%- soln in toluene, 21.5 mmol) was added in a dropwise fashion to a cooled (0 °C) solution of the diol 287 (1.30 g, 5.36 mmol) in etiier (22 mL) The solution was allowed to warm to room temperature After 2 h. the reaction was quenched by the slow droqwise addition of 1 N H 2 S0 4 until no more H evolution was observed. The mixture was then poured into ether (100 mL) and washed with water (3 x 50 mL) The aqueous layers were back-extracted with ether (100 mL). The combined organic layers were washed with bπne (50 mL), dπed (MgS0 4 ), and concentrated to give 1.25 g of of a pale yellow oil that was used without further purificauon [R f = 0.32 (2:1 hex EtOAc)]. The crude oil was dissolved in THF/DMF (2 1 , 30 mL) and the solution was cooled to 0°C tert-Butyldimethylsilyl chloπde (0.97 g, 6 43 mmol) and lmidazole (0.95 g, 13 9 mmol) were added, and the solution was surred at 0 °C for 2 h The mixture was then diluted with ether (100 mL), and washed with 1 M HCl (2 x 50 mL), sat NaHCO, (50 mL), and brine (50 mL) The organic layer was dπed (MgS0 4 ) and concentrated Chromatography (15.1 hex/EtOAc) provided 1 70 g (75% from the lactone 240) of the (E)-allyhc alcohol 289 as a colorless oil. R r = 0.20 ( 15: 1 hex/EtOAc), [ α] 23 D = -19.3° (c 0.90, CHC1 3 ); Η NMR (CDCl,, 300 MHz) δ 5.83 (dt, J = 6.7, 15 4 Hz, IH), 5.59 (ddJ = 5.6, 15.4 Hz, IH), 4.23 (m, 2H), 4.03 (dd, J = 5 6, 9.0 Hz, IH), 3.97 (m, IH), 3.85 (t, J = 10.0 Hz, IH), 3.64 (br d, J = 10.4 Hz, IH), 2.09 (q, J = 6.8 Hz, 2H), 1.38 (s, 3H), 1.32 (s, 3H), 1.25-1 45 (m, 6H). 0.92 (s, 9H), 0.89 (t, J = 6.9 Hz, 3H), 0.12 (s, 4H), 13 C NMR (CDCl,, 75 MHz) δ 132.8, 129 0, 108 4, 80.9, 77.3, 69.6, 62.0, 32.1, 31.3, 28.0, 25.9, 25.4, 22.3, 18.3, 13 9, -5.5, IR (neat) 3470 (br m), 2930 (s), 2859 (s), 1472 (m), 1380 (m) cm " '; MS (CI, NH 3 ) m/z (rel intensity) 376 [(M + NH 4 )+, 19], 359 [(M + H)+, 100], 341 (97), 318 (28), 92 (22), HRMS (CI, NH 3 ) calcd for C 19 H 38 0 4 SιH [(M + H)+] 359.2618, found 359.2603; Anal. Calcd for C, 9 H 38 0 4 Sr C, 63.64; H, 10.68 Found C, 63.62, H, 10.39. Methyl (E)-(3R,6S,7R)-3-Butyl-8-hydroxy-6,7-0-isopropylidene-dioxy-4-octenoate (292). Tπmethyl orthoacetate (2.85 g, 23.7 mmol) and propionic acid (70 mg, 0.95 mmol) were added to a soluuon of die (E)-allyhc alcohol 289 (1.70 g, 4.74 mmol) in toluene (24 mL) The flask was fitted with a distillation head and the mixture was heated at reflux, distilling off methanol as it formed. GC was used to monitor the disappearance of starting mateπal (t R -=5.4 min) and die appearance of product (t R =7.1 m ). After 16 h, the mixture was cooled to room temperature and concentrated to give 1.95 g of the desired E-γ,δ-unsaturated ester as a pale yellow oil that was used without further puπfication None of the Z-alkene isomer was detected by "H or l3 C NMR [Puπficauon of a small sample by chromatograph> ( 15 1 hex EtOAc) provided an analyucally pure sample of methyl (E)-(3R,6S.7R)-3-but\l-8-tert- butyldιmethylsilyloxy-6,7-0-ιsopropylidene-6,7-dihydroxy-4-octenoate: R f = 0.17 (15: 1 hex/EtOAc). [α f = -1.4° (c 0.35, CHC1 3 ); IH NMR (CDC1 3 , 300 MHz) δ 5.60 (dd, J = 7.4, 15 4 Hz. IH). 5.51 (dd, J = 6.6, 15.4 Hz, IH), 4.58 (t, J =6.5 Hz, IH), 4.15 (dd, J = 6.1, 11.9 Hz, IH), 3.66 (s, 3H), 3.61 (dd. J = 5.4, 10.9 Hz, IH), 3.57 (dd, J = 6.1, 10.8 Hz, IH), 2.54 (m, IH), 2.37 (dd, J = 6.5, 15.0 Hz, IH), 2.29 (dd. J = 7.8, 15.0 Hz, IH), 1.48 (s, 3H), 1.36 (s, 3H), 1.2-1.4 (m, 6H), 0.90 ( , 12H), 0.08 (s, 6H), 13 C NMR (CDC1 3 , 90 MHz) δ 172.8, 136.9, 126.0, 108.4, 78.9, 78.1, 62.8, 51.4, 39.9, 38.9, 34.1. 29.2, 27.9, 25.9, 25.4, 22.6, 18.3, 14.0, -5.3; IR (neat) 2930 (s), 2858 (s), 1742 (s) cm-1 ; MS (CI, NH,) m/z (rel intensity) 432 [(M + NH 4 )+, 100], 357 (18), 299 (9); HRMS (CI, NH 3 ) calcd for C 22 H 4 ,0,SiNH 4 [(M + NH 4 )+] 432.3145, found 423.3131 , Anal. Calcd for C 2 ,H 4 ,0,Sι. C, 63.73; H, 10.21 Found C, 63.68, H, 10.08.] The crude α,δ-unsaturated ester was dissolved in THF (25 mL), tetra-n-butylammonium fluoπde (5.2 mL of a 1 M soln. m THF, 5.2 mmol) was added, and die resulung mixture was surred at room temperature. After 1 h, the mixture was diluted with ether (100 mL), washed with water (50 L) and bπne (50 mL), then dπed (MgS0 4 ) and concentrated. Chromatography (3: 1 to 2: 1 hex/EtOAc) provided 1.05 g (74% from 289) of the title compound as a colorless oil. The C(3) stereochemistry of 292 was deπved from analysis of the most favorable transition state for the Claisen rearrangement. Rf = 0.34 (2: 1 hex/EtOAc); [α] 3 D = +10.9° (c 0.52, CHC1 3 ); 'H NMR (CDCI3, 360 MHz) δ 5.60 (dd, J = 7.5, 15 4 Hz, IH), 5.54 (dd, J = 7.2, 15.4 Hz, IH), 4.62 (t, J = 6.7 Hz, IH), 4.21 (dd, J = 6.1 , 12.1 Hz, IH), 3.66 (s, 3H), 3.56 (t, J = 6.6 Hz, 2H), 2.42 (dd, J = 5.0, 15.0 Hz, IH), 2.24 (dd, J = 9.3, 15.0 Hz, IH), 2.15 (br t, J = 6.4 Hz, IH), 1.49 (s, 3H), 1.38 (s, 3H), 1.2-1.4 (m, 6H), 0.88 (t, J = 6.9 Hz, 3H); 13 C NMR (CDCl,, 90 MHz) δ 173.1, 138.2, 125.9, 108.6, 78.3, 78.1, 61.7, 51.6, 39.7, 39.2, 34.4, 29.1, 27.8, 25.2, 22.5, 13.9; IR (neat) 3500 (br s), 2932 (s), 1738 (s) cm '; MS (CI, NH 3 ) m/z (rel intensity) 318 [(M + NH 4 )+, 45], 243 (100), 230 (83), 207 (76); HRMS (CI, NH 3 ) calcd for C 16 H 28 0,NH 4 [(M + NH 4 )+] 318.2280, found 318.2298; Anal. Calcd for C 16 H 28 0 5 : C, 63.97; H, 9.40. Found: C, 63.80; H, 9.35. 294 Methyl (E)-(3R,6S,7R)-8-Azido-3-butyl-6,7-0-isopropyIidene-dioxy-4-octenoate (294). Hydrazoic acid (8.3 mL of a 1.2 M solution in benzene, 10.0 mmol) was added to a solution of the alcohol 292 (1.00 g, 3.33 mmol) and tπphenylphosphine (1.75 g, 6.65 mmol) in benzene (17 mL). The mixture was cooled to 5°C and diethyl azodicarboxylate (1.10 mL, 6.65 mmol) was added in a dropwise fashion. The solution was then allowed to warm to room temperature. After 2 h, TLC indicated that starting material was still present. More hydrazoic acid solution (2.8 mL, 3.4 mmol), tπphenylphosphine (0.65 g, 2.5 mmol), and DEAD (0.41 mL, 2.5 mmol) were added and d e mixture was allowed to stir at room temperature for another 1 h. The mixture was then poured into hexanes (100 mL), resulting in me formaύon of a white precipitate. The mixture was filtered, and the filtrate was concentrated. Chromatography (15:1 to 10:1 hexane/EtO Ac) provided 0.915 g (84%) of the azide 294 as a colorless oil. R r = 0.30 (8:1 hex/EtOAc); [α] 23 D = +52.7° (c 1.42, CHC1 3 ); Η NMR (CDC1 3 , 300 MHz) δ 5.60 (dd, J = 8.3, 15.4 Hz, IH), 5.47 (dd, J = 7.6, 15.4 Hz, IH), 4.61 (t, J = 6.9 Hz, IH), 4.25 (ddd, J = 4.1, 6.7, 7.1 Hz, IH), 3.64 (s, 3H), 3.27 (dd, J = 7.8, 12.8 Hz, IH), 3.16 (dd, J = 4.1, 12.8 Hz, IH), 2.58 (m, IH), 2.40 (dd, J = 5.6, 15.0 Hz, IH), 2.24 (dd, J = 8.8, 15.0 Hz, IH), 1.52 (s, 3H), 1.39 (s, 3H), 1.2-1.5 (m, 6H), 0.89 (t, J = 6.8 Hz, 3H); 13 C NMR (CDC1 3 , 75 MHz) δ 172.5, 138.2, 125.2, 109.1 , 78.0, 77.2, 51.7, 51.5, 39.9, 39.1, 34.3, 29.2, 27.9, 25.4, 22.6, 14.0; IR (neat) 2932 (m), 2102 (s), 1738 (s) cm-1; MS (CI, NH 3 ) m z (rel intensity) 343 [(M + NH 4 )+, 15], 298 (100), 286 (62), 240 (18); HRMS (CI, NH,) calcd for C 16 H 27 N 3 0 4 NH 4 [(M + NH 4 )+] 343.2345; found 343.2338; Anal. Calcd for C l( ,H- 7 N,0 4 : C, 59.06; H, 8.36; N, 12.91. Found: C, 59.33; H, 8.32; N, 13.11. 296α 296/3 Methyl (3R,4R,5S,6R,7R)-8-Azido-3-butyl-4,5-epoxy-6,7-0- isopropylidenedioxyoctanoate (296α) and Methyl (3R,4S,5R,6R,7R)-8-Azido-3-butyI- 4,5-epoxy-6,7-0-isopropylidenedioxyoctanoate (296β). m-Chloroperbenzoic acid (1.48 g, technical grade, 1.18 g pure, 6.8 mmol) was added to a cooled (0 °C) solution of the azide 294 (0.89 g., 2.73 mmol) in CH 2 C1 2 (14 mL). After 24 h, the mixture was diluted with ether (50 mL) and washed with 1 M NaOH (2 x 25 mL). The aqueous layers were back-extracted with ether (2 x 25 mL) and the combined organic layers were washed with saturated NaHC0 3 (50 mL) and brine (25 mL), then dried (MgS0 4 ), filtered, and concentrated to provide 0.91 g (98% crude) of a mixture (3.5: 1 by IH NMR integration) of diastereomeric epoxides that were used without futher purification. Purification of a small sample by chromatography (10:1 hex/EtOAc gradient) provided an analytically pure sample of the major diastereomer 296α. Data for 296α: R f = 0.23 [8: 1 hex/EtOAc (2 elutions)]; [α] 23 D = +43.3° (c 0.70, CHC1 3 ); Η NMR (CDClj, 360 MHz) δ 4.36 (td, J = 4.5, 6.7 Hz, IH), 3.68 (s, 3H), 3.65 (dd, J = 6.2, 8.5 Hz, IH), 3.61 (dd, J = 4.4, 13.0 Hz, IH), 3.57 (dd, J = 6.9, 13.0 Hz, IH), 2.84 (dd, J = 2.0, 8.5 Hz, IH), 2.73 (dd, J = 2.0, 8.2 Hz, IH), 2.48 (dd, J = 6.1, 15.2 Hz, IH), 2.35 (dd, J = 7.1, 15.2 Hz, IH), 1.71 (m, IH), 1.52 (s, 3H), 1.45 (m, 3H), 1.37 (s, 3H), 1.34 (m, 3H), 0.90 (t, J = 7.1 Hz, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 172.7, 109.9, 77.9, 76.6, 60.9, 55.6, 51.6, 50.2, 38.1, 37.0, 31.3, 29.1, 27.7, 25.2, 22.7, 13.9; IR (neat) 2934 (m), 2104 (s), 1738 (s) cm "1 ; MS (CI, NH 3 ) m/z (rel intensity) 359 [(M + NH 4 )+, 43], 342 [(M + H)+, 22], 314 (100), 142 (42); HRMS (CI, NH 3 ) calcd for C 16 H 27 N 3 0 5 H [(M + H)+] 342.2029; found 342.2018; Anal. Calcd for C 16 H 27 N 3 0 5 : C, 56.29; H, 7.97; N, 12.31. Found: C, 56.66; H, 8.02; N, 12.12. (lS,2R,7R,8S,8aS)-7-Butyl-8-hydroxy-l,2-0-isopropylidene-dioxyindolizidin-5-one (299) and (lS,2R,7R,8R,8aR)-7-Butyl-8-hydroxy-l,2-0-isopropylidenedioxy indolizidin-5-one (298). Palladium hydroxide on carbon (125 mg) was added to a solution of the epoxides 296αβ (3.5: 1, 840 mg, 2.5 mmol) in MeOH/EtOAc (1:1, 35 mL). The flask was evacuated (aspirator) and purged with hydrogen three times, and the resulting heterogeneous mixture was stirred under a balloon of hydrogen. After 3 h, the hydrogen was evacuated, the mixture was filtered, and the filtrate was concentrated. The residue was redissolved in MeOH (35 mL), sodium methoxide (66 mg, 1.2 mmol) was added, and the mixture was warmed to reflux. Reaction progress was monitored by IR for the disappearance of the ester and lactone carbonyl stretches at 1730 cm " ' and 1780 cm-1 and appearance of the lactam carbonyl stretch at 1625 cm "1 . After 60 h, the mixture was cooled to room temperature and concentrated. The residue was dissolved in CH 2 Cl 2 /MeOH (20:1, 10 mL), Florisil (1 g) was added, and the mixture was stirred for 15 min. The suspension was then filtered through Celite and the filtrate was concentrated. Chromatography ( 100: 1 to 50: 1 CH 2 Cl,/MeOH) provided 127 mg (18%) of the lactam 299 as a white crystalline solid followed b 415 mg (60%) of the lactam 298 as a white crystalline solid. The stereochemistry of 299 and 298 was assigned based on spectral comparison to lactams 222 and 253. Data for 299 (minor): R f = 0.31 (20: 1 CHCI3/Me0H); [α] 23 D = -60.0° (c 0.45, CHC1,); mp 194 °C; Η NMR (CDC1 3 , 300 MHz) δ 4.74 (td, J = 2.5, 6.3 Hz, IH), 4.51 (t, J = 6.0 Hz, IH). 4.18 (dd. J = 6.4. 13.7 Hz, IH), 3.42 (dd, J = 2.3, 13.6 Hz, IH), 3.35 (m, 2H), 2.65 (dd, J = 5.2. 17.2 Hz, IH). 2.4 (br s. IH), 1.97 (dd, J = 11.2, 17.2 Hz, IH), 1.7-2.0 (m, 3H), 1.57 (s, 3H), 1.38 (s, 3H), 1.05- 1.4 (m, 6H), 0.90 (t, J = 6.9 Hz, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 167.9, 114.1, 84.1, 73.9, 67.5, 49.1 , 39.6, 35.8. 30.9, 28.1, 27.7, 25.5, 22.7, 14.0; IR (neat) 3310 (br m), 2931 ( ), 1604 (s) cm-1 ; MS (CI, NH,) m/z (rel intensity) 284 [(M + H)+, 100], 226 (20), 208 (12); HRMS (CI, NH,) calcd for C,«H 25 N0 4 H [(M + H)+] 284.1862; found 284.1866; Anal. Calcd for C 15 H 25 N0 4 : C, 63.58; H, 8.89; N, 4.94. Found: C, 63.52; H, 8.86; N, 4.85. Data for 298 (major): R f = 0.26 (20: 1 CHCl 3 /MeOH); [α] 23 D = -40.0° (c 0.55, CHC1,); mp 131 °C; 'H NMR (CDC1 3 , 300 MHz) δ 4.76 (dd, J = 4.1, 5.9 Hz, IH), 4.71 (t, J = 5.9 Hz, IH), 4.26 ( , IH), 4.22 (d, J = 13.4 Hz, IH), 3.38 (dd, J = 4.0, 6.4 Hz, IH), 3.25 (br s, IH), 3.02 (dd, J = 4.7, 13.5 Hz, IH), 2.44 (dd, J = 5.7, 17.2 Hz, IH), 2.33 (dd, J = 4.8, 17.2 Hz, IH), 2.01 (m, IH), 1.72 (m, IH), 1.39 (s, 3H), 1.32 (s, 3H), 1.1-1.5 (m, 5H), 0.90 (t, J = 6.8 Hz, 3H); 13 C NMR (CDCl,, 90 MHz) δ 168.7, 1 11.7, 79.9, 77.6, 66.3, 63.8, 50.1, 38.0, 33.8, 29.5, 27.4, 26.3, 24.6, 22.7, 14.0; IR (neat) 3280 (br m), 2922 (m), 1621 (s) cm-l; MS (CI, NH 3 ) m/z (rel intensity) 284 [(M + H)+, 100], 206 (4); HRMS (CI, NH,) calcd for C 15 H 25 N0 4 H [(M + H)+] 284.1862; found 284.1856; Anal. Calcd for C„H,,N0 4 : C, 63.58; H, 8.89; N, 4.94. Found: C, 63.29; H, 8.88; N, 4.92. OH H " 302 (lS,2R,7R,8R,8aR)-7-Butyl-8-hydroyx-l,2-0-isopropyIidene-dioxyindolizidine (302) Reduction of the lactam 298 (300 mg, 1.06 mmol) was carried out with borane-methyl sulfide complex. ^ ,. .., e O 98/14445 - 30 - Chromatography (100: 1 to 50:1 CH : Cl,/MeOH gradient) provided 280 mg (98%) of the indolizidine 302 as a white crystalline solid. R r = 0.22 (20: 1 CHCl,/MeOH); [α] 2, D = -56.8° (c 0.74. CHC1,); mp 38 °C. 'H NMR (CDC1 3 , 300 MHz) δ 4.63 (dd, J = 4.2, 6.2 Hz, IH, HI), 4.60 (dd, J = 4.0, 6.2 Hz. IH. H2). 3.99 (m, IH, H8), 3.12 (d, J = 10.7 Hz, IH, H^), 2.75 (ddd, J = 2.7, 4.2, 10.9 Hz, IH, H,^), 2.15 (dd. J = 3.9, 10.7 Hz, IH, H 3a .), 2.10 (dt, J = 4.2, 11.0 Hz, IH, H 5 „), 1.93 (m, 3H, H 8a +H 7 +H OH ), 1.5- 1.8 (m. 3H). 1.51 (s, 3H), 1.33 (s, 3H), 1.1-1.4 (m, 5H), 0.90 (t, J = 7.0 Hz, 3H, H 12 ); 13 C NMR (CDCl,, 75 MHz) δ 111.3, 79.6, 78.4, 69.9, 67.1, 59.9, 46.3, 38.3, 30.5, 27.4, 26.1, 25.0, 23.7, 23.1. 14.2; IR (neat) 3450 (br m), 2930 (s), 2870 (m), 2788 ( ), 1377 (m) cm-1; MS (CI, NH 3 ) m z (rel intensity) 270 [(M + H)+. 100], 252 (46), 194 (36); HRMS (CI, NH 3 ) calcd for C 15 H 27 N0 3 H [(M + H)+] 270.2069; found 270.2061 ; Anal. Calcd for C 15 H 27 N0 3 : C, 66.88; H, 10.10; N, 5.20. Found: C, 66.53; H, 10.39; N, 5.27. (lS,2R,7R,8S,8aS)-7-Butyl-8-hydroxy-l,2-0-isopropylidene-dioxyindolizidine (306) Reduction of the lactam 299 (120 mg, 0.42 mmol) was carried out with borane-methyl sulfide complex using the procedure described above for the reduction of 222. Chromatography (100: 1 to 50: 1 CH2Cl 2 /MeOH gradient) provided 105 mg (92%) of the indolizidine 306 as a white crystalline solid. R f = 0.31 (20:1 CHCl 3 /MeOH); [α] 23 D = -65.1° (c 0.37, CHC1 3 ); mp 82 °C; 'H NMR (CDCl,, 300 MHz) δ 4.71 (td, J = 5.2, 6.6 Hz, IH, H2), 4.44 (dd, J = 6.1, 7.3 Hz, IH, HI), 3.37 (dd, J = 6.4, 9.3 Hz, IH, H 3cq ), 3.11 (br t, J = 8.6 Hz, IH, H 8 ), 2.90 (m, IH, H 5eq ), 2.38 (dd, J = 5.1 , 9.3 Hz, IH, H 3 „), 2.17 (td, J = 2.8, 11.3 Hz, IH, H 5 „), 2.06 (br s, IH, H 0H ), 2.01 (dd, J = 6.0, 9.1 Hz, IH, H 8a ), 1.79 (m, 2H), 1.53 (s, 3H), 1.34 (s, 3H), 1.1-1.5 (m, 7H), 0.90 (t, J = 7.0 Hz, 3H, H12); 13 C NMR (CDC1 3 , 75 MHz) δ 1 14.3, 83.6, 77.9, 75.3, 74.1, 59.6, 51.3, 43.7, 31.1, 29.4, 28.9, 27.2, 25.1 , 23.0, 14.1; IR (neat) 3335 (br m), 2913 (s), 2858 ( ), 2805 (m), 1381 (m) cm 1 ; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 270 [(M + H)+, 100], 252 (27), 194 (31); HRMS (CI, CH 4 and NH 3) calcd for C 15 H 27 N0 3 H [(M + H)+] 270.2069; found 270.2080; Anal. Calcd for C 15 H 27 N0 3 : C, 66.88; H, 10.10; N, 5.20. Found: C, 66.76; H, 10.36; N, 5.20. 98/14445 - 31 304 (lS,2R,7R,8R,8aR)-7-Butyl-1.2,8-trihydroxyindolizidine [(7R)-7-Butyl-swainsonine] (304). A solution of the indolizidine 302 (97 mg, 0.33 mmol) in THF (2 mL) was treated with 6 N HCl (2 mL). After 24 h, the solution was concentrated The residue was dissolved in MeOH (5 mL), Dowex 1x8 200 OH- resin (500 mg) was added, and the mixture was surred at room temperature After 15 min. me mixture was filtered, and the filtrate concentrated to give a white solid. Recrystallization from EtOAc provided 61 mg (81%) of the title compound (304) in three crops R f = 0.23 (50.25: 1 EtOAc/EtOH/Aq NH 4 OH), [α] 23 D = -88.1° (c 0.75, MeOH); mp 156 °C, Η NMR (CD30D, 360 MHz) δ 4 19 (m, IH), 4.09 (dd, J = 3.5, 5.5 Hz, IH), 3.94 (dd, J = 4.8, 10.1 Hz, IH), 3.28 (m, IH), 2.85 (d, J = 10.3 Hz, IH), 2.66 (m, IH), 2 42 (dd, J = 7.9, 9.9 Hz, IH), 2.1 (m, IH), 1 98 (dd, J = 2.9, 10 0 Hz, IH), 1.87 (m, IH), 1.56-1.72 (m, 3H), 1.15-1 45 (m, 5H), 0.90 (t, J = 6.7 Hz, 3H); 13 C NMR (CD,OD, 90 MHz) δ 71.1 , 70.1, 69.8, 68.6, 63.2, 47.8, 39.8, 31.8, 27.7, 24.8, 24.3, 14.6, IR (neat) 3370 (br m), 2934 (s), 2880 (m), 2821 (m) cm-1; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 230 [(M + H)+, 100], 212 (67), 194 (30), 176 (21); HRMS (CI, CH 4 and NH 3 ) calcd for C 12 H 23 N0 3 H [(M + H)+] 230.1756, found 230.1746, Anal Calcd for C 12 H 23 N0 3 : C, 62.84; H, 10.11; N, 6.11 Found C, 62 46, H, 10.08, N, 6.09 Example 5 Process for the Preparation of (lS,2R,7R,8S,8aS)-7-Butyl-l,2,8-trihydroxyindolizidine [(7R)-7-Butyl-8,8a-diepiswainsonine] (308) 308 The acetonide of the indolizidine 306 (80 mg, 0.27 mmol) was hydrolyzed with 6 N HCl in THF. Recrystallization from EtOAc provided 51 mg (83%) of the title compound (308) in three crops. R f = 0.37 (50:25:1 EtOAc/EtOH/Aq. NH 4 OH); [α] 23 D = -60.6° (c 1.30, MeOH); p 120 °C, Η NMR (CDC1 3 , 360 98/14445 - 32 - MHz) δ 4.21 (dd. J = 6 4, 11.9 Hz. IH), 3 7-4 3 (br m, 3H, D20 exchangeable), 3 91 (t, J = 7 3 Hz. IH ) . 3 46 (dd, J = 6.8, 9.8 Hz, IH), 3 19 (t, J = 9.0 Hz, IH), 2 91 (d. J = 11.2 Hz, IH). 2.22 (dd. J = 4.9. 9 9 Hz, IH), 2.08 (dt, J = 3, 11 Hz, IH), 1.90 (t, J = 8.2 Hz, IH), 1.82 (m, 2H), 1 0- 1.5 (m. 7H). 0 90 (t. J = 7.0 Hz, 3H); ,3 C NMR (CDC1 3 , 90 MHz) δ 75.0, 71.6, 67.8, 61.2, 51.7, 43.5, 31 1, 29.6. 28.9. 23.1, 14.1 ; IR (neat) 3300 (br s), 2929 (s), 2860 (m), 2805 (m), 1466 (m) cm-1, MS (CI. CH and NH,) m/z (rel intensity) 230 [(M + H)+, 58], 212 (100), 194 (14), HRMS (CI, CH 4 and NH,) calcd for C ι: H ; ,NO,H [(M + H)+] 230.1756, found 230.1759, Anal Calcd for C. 2 H 2 ,N0 3 - C, 62.84, H, 10.1 1 , N. 6.1 1 Found: C, 62.47, H, 10.11; N, 6.13. Example 6 Production of (lS,2R,7S,8R,8aR)-7-[2-(Benzyloxy)ethyl]-l,2,8-trihydroxyindolizidine [(7S)-7-(2-Benzyloxyethyl)swainsonine] (305). (5S,6S,7R)-l-Benzyloxy-5,8-dihydroyx-6,7-0-isopropyIidene-dioxy-3-octyne (288). 2,3-O-Isopropylιdene-D-erythrose was prepared via the dnsobutylaluminum hydnde reduction of 2,3-0- lsopropylidene-D-erythronolactone. 4-Benzyloxybutynylmagnesιum chloπde was prepared by adding isopropylmagnesium chloπde (10.0 mL of a 2 M soln. in ether, 20 mmol) to a cooled (0 °C) solution of 4- benzyloxy-1-butyne (3.20 g, 20.0 mmol) in THF (20 mL) and then allowing the solution to warm to room temperature The 4-benzyloxybutynyl-magnesιum chloπde solution was transferred via cannula into a cooled (-78 °C) solution of 2,3-O-ιsoρropylιdene-D-erythrose (1.30 g, 8.1 mmol) The resuthng mixture was stirred for 30 mm at -78°C, and was then allowed to warm slowly to 0°C After 6h, the reaction was quenched by the addition of saturated aqueous NH C1 (100 mL) The mixture was extracted with ether (2 x 100 mL). The combined organic phases were washed with water (50 mL) and bπne (50 mL), and then dπed (MgS0 4 ), and concentrated. Chromatography (3: 1 to 1:1 hex/EtOAc gradient) provided 2.62 g (100%) of the title compound as a colorless oil The stereochemistry of 288 was assigned based on analogy to the results reported by Mekki et al. on the addition of similar alkynl Gπgnard reagents to 2,3-O-ιsopropyhdene- D-erythrose. R f = 0.10 (2:1 hex EtOAc); [α] 23 D = -18.0° (c 0.95, CHC1 3 ); Η NMR (CDC1 3 , 300 MHz) δ 7.2-7.4 (m, 5H), 4.54 (s, 2H), 4.52 (m, IH), 4.29 (td, J = 4.3, 6.0 Hz, IH), 4.19 (t, J = 6.3 Hz, IH), 3.88 98/14445 - 33 - (m, 3H), 3 60 (t, J = 6.8 Hz, 2H), 3 10 (m. IH), 2 54 (td. J = 1 9. 6 8 Hz. 2H). 1 48 (s. 3H). 1 37 (s. 3H). 13C NMR (CDCI3, 75 MHz) δ 137.9, 128.3, 127.7, 108.5, 83 8, 79.5, 79.2. 77.3. 73 0. 68 2. 61 7. 60.4, 27.4, 25.2, 20.3, IR (neat) 3390 (br, s), 2985 (m), 2871 (m), 1371 (s) cm ', MS (CI. NH,) m/z (rel intensity) 338 [(M + NH 4 )+, 93], 280 (100), 203 (77), 185 (60), HRMS (CI, NH3) calcd for C 18 H 2 0,NH 4 [(M + NH 4 )+] 338.1967, found 338.1961 , Anal. Calcd for C l8 H 24 0 5 C, 67 48, H, 7.55 Found C, 67.13, H, 7.59 (E)-(5S,6S,7R)-l-Benzyloxy-8-tert-butyldimethylsilyloxy-4-hydroxy-2,3-0- isopropyIidene-dioxy-3-octene (290). Sodium bιs(2-medιoxyethoxy)-alumιnum hydπde ιRed-.AJ) (3.77 mL of a 70% soln. in toluene, 12.2 mmol) was added in a dropwise fashion to a cooled (0 °C) soluuon of the diol 288 (1.20 g, 3.75 mmol) in ether (12 mL). The solution was allowed to warm to room temperature. After 3 h, the mixture was again cooled to 0 °C and the reacuon was quenched by the slow dropwise addmon of IN H 2 S0 4 until no more bubbling was observed The mixture was poured into ether (100 mL) and washed with water (3 x 50 mL) The aqueous layers were back-extracted with ether (100 mL) The combined organic layers were washed with bπne (50 mL), then dπed (MgS0 4 ), and concentrated to give 1.10 g of crude (E)-alkene that was used witiiout further puπfication [A small sample was puπfed by chromatography (4: 1 hex EtOAc) to obtain an analytically pure sample of (E)-(5S,6S,7R)- 1 -Benzyloxy-2,3- 0-ιsopropyhdene-l,2,3,4-tetrahydroxy-3-octene: R r = 0.32 (2: 1 hex/EtOAc - 3 elutions), [α] 23 D = -25.3° (c 0.75, CHC1-); Η NMR (CDC1 3 , 300 MHz) δ 7.2-7.4 (m, 5H), 5.81 (dt, J = 6.5, 15.6 Hz, IH), 5.67 (dd, J = 6.0, 15.5 Hz, IH), 4.51 (s, 2H), 4.27 (m, 2H), 4.01 (dd, J = 5.8, 8.3 Hz, IH), 3.7-3.9 (m, 2H), 3.54 (t, J = 6.6 Hz, 2H), 3.22 (m, 2H), 2.41 (q, J = 6.5 Hz, 2H), 1.41 (s, 3H), 1.34 (s, 3H), 13 C NMR (CDC1 3 , 75 MHz) δ 138.2, 131.2, 130.0, 128.3, 127.6, 127.5, 108.3, 79.6, 77 4, 72.9, 70.5, 69.6, 60.8, 32.8, 27.8, 25.3; IR (neat) 3375 (br s), 2985 (m), 2934 (s), 2868 (s), 1380 (m) cm-1; MS (CI, NH 3 ) m/z (rel intensity) 340 [(M + NH 4 )+, 68], 322 (68), 282 (100), 247 (44), 91 (50), HRMS (CI, NH 3 ) calcd for C 18 H 26 0 5 NH» [(M + NH 4 )+] 340.2124, found 340.2137; Anal. Calcd for C 18 H 26 0 5 - C, 67.06, H, 8.13. Found: C, 66.93; H, 8.05.] „ Λ Λ ΛM 98/14445 - 34 - The crude E-alkenyl diol was dissolved in THF/DMF (2 1 , 15 mL). and the solution was cooled to 0°C tert-Butyldimethylsilyl chloπde (0 59 g, 3 9 mmol) and lmidazole (0 58 g, 8 5 mmol) were added and the soluuon was stirred at 0 °C for 2 h The mixture was then diluted wiUi ether ( 100 mL) and washed with 1 M HCl (2 x 50 mL), sat NaHC0 3 (50 mL), and bπne (50 mL) The organic layer was dπed (MgS0 ) and concentrated Chromatography (10 1 hex EtOAc) provided 1 15 g (73% from 288) of the (E)-allyhc alcohol 290 as a colorless oil R f = 0 66 (2 1 hex EtOAc), [α] 23 D = - 17 6° (c 1 06, CHC1,), Η NMR (CDCl,, 300 MHz) δ 7 2-7 4 (m, 5H), 5 86 (dtd, J = 1 1 , 6 7, 15 6 Hz, IH), 5 70 (dd, J = 5 3, 15 5 Hz, IH), 4 51 (s, 2H), 4 27 (m, IH), 4 23 (ddd, J = 3 8, 5 4, 9 7 Hz, IH), 4 13 (d, J = 3 2 Hz, IH), 4 03 (dd. J = 5 5 9 1 Hz, IH), 3 84 (t, J = 10 4 Hz, IH), 3 63 (dd, J = 3 6, 10 5 Hz, IH), 3 54 (t, J = 7 0 Hz, 2H). 2 42 (q, J = 6 8 Hz, 2H), 1 38 (s, 3H), 1 32 (s, 3H), 0 91 (s, 9H), 0 12 (s, 6H), 13C NMR (CDCl,, 75 MHz) δ 138 5, 131 0, 128 5, 128.2, 127 5, 127 3, 108 4, 80 7, 77 2, 72 8, 69 8, 69 4, 61 9, 32 9, 28 0, 25 8, 25 3, 18.2, -5 5, IR (neat) 3450 (br m), 2934 (s), 2858 (s) cm- 1 , MS (CI, NH 3 ) m/z (rel intensity) 454 [(M + NH 4 )+, 6], 437 [(M + H)+, 4], 419 (100), 396 (43), 361 (43), HRMS (CI, NH,) calcd for C^H M H [(M + H)+] 437 2723 found 437 2728, Anal Calcd for C 24 H 40 O,Sι C, 66 02, H, 9 23 Found C, 65 81 , H, 9 08 Methyl E-(3R,6S,7R)-3-[2-(Benzyloxy)ethyI]-8-hydroxy-6,7-0-isopropyIidenedioxy-4- octenoate (293). Tπmethyl orthoacetate (1 15 g, 9 6 mmol) and propionic acid (30 mg, 0 38 mmol) were added to a solution of the E-allyhc alcohol 290 (0 840 g, 1 92 mmol) in toluene (10 mL) The flask was fitted with a distillation head, and the mixture was heated at reflux, distilling off methanol as it foimed After 16 h, the mixture was cooled to room temperature and concentrated Chromatography (10 1 to 8 1 hex EtOAc gradient) provided 0930 g (88%) of the silyl ether protected E-γ,δ-unsaturated ester as a colorless oil None of the Z-alkenyl isomer was detected by IH or 13C NMR [Rf = 0 33 (8 1 hex EtOAc), [α] 23 D = +8 1° (c 1 71, CHC1 3 ), Η NMR (CDC1 3 , 300 MHz) δ 7 2-7 4 (m, 5H), 5 62 (dd, J = 7 4, 15 4 Hz, IH), 5.54 (dd, J = 6 6, 15 4 Hz, IH), 4 55 (t, J = 6.5 Hz, IH), 4 47 (s, 2H), 4 14 (dd, J = 5.9, 12 1 Hz, IH), 3 63 (s, 3H), 3 58 (d, J = 5 8 Hz, 2H), 3 49 (m, 2H), 2 77 (m, IH), 2 41 (dd, J = 6.3, 15.2 Hz, IH), 2 31 (dd, J = 7 8, 15 2 Hz, IH), 1 78 (m, IH), 1 63 (m, IH), 1 46 (s, 3H), 1 36 (s, 3H), 0 90 (s, 9H), 0.08 (s, 6H), 13C NMR (CDC1 3 , 90 MHz) δ 172.2, 138 4, 136 1, 128.2, 127.5, 127 4, 98/14445 35 126.6, 108 4, 78.9, 78.1 , 72.9, 68.0, 62.7, 51.3, 39.7, 36.0, 34.3. 27.9. 25.9. 25.4. 18.3, -5.2. IR (neat) 2930 (s), 2856 (s), 1741 (s) cm- 1; MS (CI, NH 3 ) m/z (rel intensity) 510 [(M + NH 4 )+. 27]. 452 (55). 435 (100), 327 (84), 195 (84); HRMS (CI, NH 3 ) calcd for C^H^O^SiNH, [(M + NH 4 )+] 510.3251. found 510.3237; Anal. Calcd for C, 65.82; H, 9.00. Found: C, 65.86; H, 8.78.] Tetra-n-butylammonium fluoride (2.0 mL of a 1 M soln. in THF, 2.0 mmol) was added to a solution of the alkenyl ester (0.90 g, 1.83 mmol) in THF (9 mL). After 1 h, the mixture was diluted with ether (50 mL), washed with water (25 mL) and bπne (25 mL), then dπed (MgS0 ) and concentrated Chromatography (2:1 hex/EtOAc) provided 0.62 g (90%) of the alcohol 293 as a colorless oil. Rf = 0.10 (2: 1 hex/EtOAc); [α] 23 D = +28.8° (c 0.80, CHC1 3 ); IH NMR (CDCl,, 360 MHz) δ 7.2-7.4 (m. 5H). 5.60 (dd, J = 7.7, 15.4 Hz, IH), 5.54 (dd, J = 7.2, 15.4 Hz, IH), 4.59 (t, J = 6.8 Hz, IH). 4.47 (s, 2H). 4.19 (dd, J = 6.0, 12.4 Hz, IH), 3.64 (s, 3H), 3.52 (t, J = 6.2 Hz, 2H), 3.47 (m, 2H), 2.77 (m, IH), 2.45 (dd, J = 5.1, 15.2 Hz, IH), 2.38 (t, J = 6.4 Hz, IH), 2.28 (dd, J = 9.2, 15.2 Hz, IH), 1.74 (m, IH), 1.63 (m, IH), 1.48 (s, 3H), 1.37 (s, 3H); 13C NMR (CDCl,, 90 MHz) δ 172.7, 138.2, 136.8, 128.2, 127.5, 127.4, 126.4, 108.5, 78.2, 77.8, 72.8, 67.7, 61.5, 51.5, 39.5, 36.1, 34.3, 27.7, 25.1 ; IR (neat) 3488 (m), 2934 (s), 2868 (s), 1737 (s) cm-1, MS (CI, NH,) m/z (rel intensity) 396 [(M + NH 4 )+, 32], 321 (73), 303 (63), 213 (64), 195 (100); HRMS (CI, NH 3 ) calcd for C 2l H 30 O 6 NH 4 [(M + NH 4 )+] 396.2386, found 396.2398; Anal. Calcd for C 21 H 30 O 6 : C, 66.65; H, 7.99. Found: C, 66.79; H, 7.92. Methyl E-(3R,6S,7R)-8-Azido-3-[2-(benzyloxy)ethyI]-6,7-0-isopropylidenedi oxy-4- octenoate (295). Hydrazoic acid (4.0 mL of a 1.2 M solution in benzene, 4.8 mmol was added to a solution of the alcohol 293 (0.60 g, 1.6 mmol) and tπphenylphosphine (0.84 g, 3.2 mmol) in benzene (8 mL). The mixture was cooled to 5°C and diethyl azodicarboxylate (0.55 mL, 3.2 mmol) was added in a dropwise fashion. The solution was then allowed to warm to room temperature. After 2 h, TLC indicated tiiat starting material was still present. More hydrazoic acid solution (1.3 mL, 1.6 mmol), triphenylphosphine (0.31 g, 1.2 mmol), and DEAD (0.20 mL, 1.2 mmol), were added and the mixture was allowed to stir at room temperature for another 1 h. The mixture was then poured into hexanes (50 mL), resulting in the formation of a white precipitate. The mixture was filtered, and the filtrate was concentrated. Chromatography (8:1 to 6:1 hexane/EtOAc) provided 0.560 g (87%) of the azide 295 as a colorless oil. R f = 0.17 (6: 1 hex/EtOAc); [α] 23 D = +52.2° (c 1.25, CHC1 3 ); IH NMR (CDC1 3 , 360 MHz) δ 7.2-7.4 (m, 5H), 5.62 (dd, J = 8.6, 15.4 Hz, IH), 5.47 (dd, J = 7.6, 15.4 Hz, IH), 4.59 (t, J = 7.1 Hz, IH), 4.59 (ABq, J = 12.0 Hz, Dn = 13.0 Hz, 2H), 4.23 (ddd, J = 4.1, 6.6, 7.8 Hz, IH), 3.64 (s, 3H), 3.21 (dd, J = 7.8, 12.8 Hz, IH), 3.09 (dd, J = 4.0, 12.8 Hz, IH), 2.79 (m, IH), 2.44 (dd, J = 5.5, 15.2 Hz, IH), 2.29 (dd, J = 8.8, 15.2 Hz, IH), 1.77 (m, IH), 1.65 (m, IH), 1.51 (s, 3H), 1.37 (s, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 172.3, 138.3, 137.4, 128.3, 127.6, 127.5, 125.7, 109.1, 77.8, 77.1, 72.9, 67.8, 51.5, 39.6, 36.1, 34.3, 27.8, 25.2; IR (neat) 2988 (m), 2935 (m), 2862 (m), 2101 (s), 1738 (s) cm " '; MS (CI, NH 3 ) m/z (rel intensity) 421 [(M + NH 4 )+, 3], 376 (100), 318 (18); HRMS (CI, NH 3 ) calcd for C 21 H 29 N 3 0 5 NH 4 [(M + NH4)+] 421.2451 ; found 421.2444; Anal. Calcd for C 21 H 29 N 3 0 5 : C, 62.51 ; H, 7.24; N, 10.41. Found: C, 62.62; H, 7.36; N, 10.54. Methyl(3R,4R,5S,6R,7R)-8-Azido-3-[2-(benzyloxy)ethyl]-4,5-epoxy-6,7-0- isopropylidene-dioxyoctanoate (297α) and Methyl (3R,4S,6R,6R,7R)-8-Azido-3-[2- (benzyloxy)ethyI]-4,5-epoxy-6,7-0-isopropylidenedioxyoctanoate (297β). m- Chloroperbenzoic acid (0.67 g, technical grade, 0.54 g pure, 3.1 mmol) was added to a cooled (0 °C) solution of the azide 295 (0.50 g, 1.2 mmol) in CH 2 C1 2 (6 mL). After 24 h, the mixture was diluted with ether (50 mL) and washed with 1 M NaOH (2 x 25 mL). The aqueous layers were back-extracted with ether (2 x 25 mL), and the combined organic layers were washed with saturated NaHC0 3 (25 mL) and brine (25 mL), then dried (MgS0 4 ), filtered, and concentrated. Chromatography (4:1 hex/EtOAc) provided 475 mg (91%) of a mixture (3:1 by IH NMR integration) of epoxides 297α and 297β. R f = 0.30 [6:1 hex/EtOAc (3 elutions)]; 'H NMR (CDC1 3 , 360 MHz, major isomer) δ 7.2-7.4 (m, 5H), 4.50 (s, 2H), 4.34 (ddd, J = 3.9, 6.5, 7.2 Hz, IH), 3.66 (s, 3H), 3.65 (dd, J = 5.7, 8.9 Hz, IH), 3.58 (m, 3H), 3.50 (dd, J = 7.3, 13.1 Hz, IH), 2.83 (m, 2H), 2.49 (dd, J = 6.2, 15.4 Hz, IH), 2.42 (dd, J = 6.7, 15.4 Hz, IH), 1.75 (m, IH), 1.80 (m, 2H), 1.50 (s, 3H), 1.35 (s, 3H); 13 C NMR (CDC1 3 , 90 MHz, major isomer) δ 172.4, 138.3, 128.3, 127.54, 127.47, 109.9, 77.7, 76.6, 72.8, 67.2, 60.5, 55.3, 51.6, 50.4, 36.6, 35.1, 31.2, 27.5, 25.0; IR (neat) 2988 (m), 2935 (m), 2102 (s), 1738 (s) cm " '; MS (CI, NH 3 ) m/z (rel intensity) 437 [(M + NH4)+, 34], 392 (100), 360 (60), 143 (14), 108 (50); HRMS (CI, NH 3 ) calcd for C 21 H 29 N 3 0 6 NH 4 [(M + NH4)+] 437.2400; found 437.2382; Anal. Calcd for C 21 H 29 N 3 0 6 : C, 60.13; H, 6.97; N, 10.02. Found: C, 60.1 1 ; H, 7.04; N, 9.96. (lS,2R,7R,8S,8aS)-7-[2-(Benzyloxy)ethyl]-8-hydroxy-l,2-0-isopropylidenedioxy- indolizidin-5-one (301) and (lS,2R,7R,8R,8aR)-7-[2-(Benzyloxy)ethyl]-8-hydroxy-l,2- O-isopropylidenedioxyindolizidin-5-one (300). Palladium hydroxide on carbon (50 mg) was added to a solution of the epoxides 297αβ (320 mg, 0.76 mmol) in MeOH/EtOAc (1:1, 12 mL). The flask was evacuated (aspirator) and purged with hydrogen three times, and the resulting heterogeneous mixture was stirred under a balloon of hydrogen. After 3 h, the hydrogen was evacuated, the mixture was filtered, and the filtrate was concentrated. The residue was redissolved in MeOH (12 mL), sodium methoxide (21 mg, 0.38 mmol) was added, and the mixture was warmed to reflux. Reaction progress was monitored by IR for the disappearance of the ester and lactone carbonyl stretches at 1730 cm-1 and 1780 cm "1 and appearance of the lactam carbonyl stretch at 1625 cm-1. After 48 h, the mixture was cooled to room temperature and concentrated. The residue was dissolved in CH 2 Cl 2 /MeOH (20:1, 10 mL), Florisil (1 g) was added, and the mixture was stirred for 15 min. The suspension was then filtered through Celite and the filtrate was concentrated. Chromatography (100: 1 to 50:1 CH 2 Cl 2 /MeOH) provided 47 mg (17%) of the lactam 301 as a white crystalline solid followed by 188 mg (68%) of the lactam 300 as a colorless oil that crystallized upon standing. The stereochemistry of 301 and 300 was assigned based on spectral comparison with the lactams 253 and 222. Data for 301 (minor): R f = 0.28 (20:1 CHCl 3 /MeOH); [α] 23 D = -33.3° (c 0.45, CHC1 3 ); mp 109 °C; ■ H NMR (CDCl j , 300 MHz) δ 7.2-7.4 (m, 5H), 4.72 (td, J = 2.9, 6.5 Hz, IH), 4.54 (m, IH), 4.53 (ABq, J = 12.0 Hz, Dn = 27.4 Hz, 2H), 4.19 (dd, J = 6.5, 13.6 Hz, IH), 3.61 (ddd, J = 3.6, 6.0, 9.6 Hz, IH), 3.51 (ddd, J = 3.3, 8.3, 9.6 Hz, IH), 3.38 (m, 3H), 2.54 (m, IH), 1.95-2.15 (m, 2H), 1.7-1.9 (m, 2H), 1.58 (s, 3H), 1.36 (s. 3H); 13 C NMR (CDCl,, 75 MHz) δ 167.3. 137.0, 128.5. 127.9. 127.8. 1 13.9. 84.1, 76.9, 73.6, 73.4, 67.8, 67.7, 49.3, 39.4, 36.9, 32.9, 27.7, 25.4; IR (neat) 3330 (br m). 2936 (m). 2870 (m), 1621 (s) cm " '; MS (CI, NH,) m/z (rel intensity) 362 [(M + H)+, 100]; HRMS (CI. NH,) calcd for C 20 H 27 NO 5 H [(M + H)+] 362.1967; found 362.1965; Anal. Calcd for C 20 H ;7 NO 5 : C, 66.46; H, 7.53; N, 3.88. Found: C, 66.39; H, 7.54; N, 3.91. Data for 300 (major): R f = 0.25 (20: 1 CHCl 3 /MeOH); [α] 23 D = -36.4° (c 0.55. CHC13); mp 96-98 °C; IH NMR (CDC1 3 , 300 MHz) δ 7.2-7.4 (m, 5H), 4.71 (m, 2H), 4.55 (s, 2H), 4.25 (m, IH). 4.22 (d, J = 13.3 Hz, IH), 3.85 (d, J = 5.9 Hz, IH), 3.64 (ddd, J = 4.1, 5.3, 9.5 Hz, IH), 3.56 (td, J = 3.2. 9.4 Hz. IH), 3.35 (dd, J = 4.0, 6.3 Hz, IH), 3.01 (dd, J = 4.7, 13.5 Hz, IH), 2.39 (d, J = 5.4 Hz. 2H), 2.23 (m, IH), 1.97 (m, IH), 1.61 (m, IH), 1.39 (s, 3H), 1.31 (s, 3H); 13 C NMR (CDCl,. 75 MHz) δ 168.2, 137.3, 128.5, 127.9, 127.8, 111.8, 80.0, 77.6, 73.4, 68.7, 66.0, 63.9, 50.1, 37.1, 35.5, 29.8, 26.4, 24.7; IR (neat) 3370 (br m), 2935 (m), 2864 (m), 1633 (s) cm-1 ; MS (CI, NH 3 ) m/z (rel intensity) 362 [(M + H)+, 100], 272 (18); HRMS (CI, NH3) calcd for C 20 H 27 NO 5 H [(M + H)+] 362.1967; found 362.1958; Anal. Calcd for C 20 H 27 NO 5 : C, 66.46; H, 7.53; N, 3.88. Found: C, 66.57; H, 7.51 ; N, 3.87. (lS,2R,7R,8R,8aR)-7-[2-(Benzyloxy)ethyl]-8-hydroxy-l,2-0-isopropyIidenedioxy- indolizidine (302) Reduction of die lactam 300 (75 mg, 0.21 mmol) was carried out with borane- methyl sulfide complex. Chromatography (100:1 to 50:1 CH 2 Cl 2 /MeOH gradient) provided 55 mg (76%) of the indolizidine 302 as a colorless oil. Rf = 0.31 (20:1 CHCl 3 /MeOH); [α] 23 D = -61.8° (c 0.66, CHC13); IH NMR (CDC13, 300 MHz) 1.2-1 A (m, 5H), 4.68 (dd, J = 4.4, 6.2 Hz, IH, HI), 4.59 (dd, J = 4.2, 6.2 Hz, IH, H2), 4.52 (ABq, J = 11.9 Hz, Dn = 14.9 Hz, 2H), 3.96 (m, IH, H8), 3.60 ( , IH, H10), 3.47 (dt, J = 4.6, 9.1 Hz, IH, H10), 3.12 (d, J = 10.6 Hz, IH, H3eq), 3.03 (d, J = 3.7 Hz, IH, HOH), 2.79 (ddd, J = 2.7, 4.1, 10.8 Hz, IH, H5eq), 2.0=2.2 (m, 4H, H3ax, 5ax, 7,9), 1.8-1.9 (m, 2H, H6), 1.60 (m, IH, H8a), 1.51(s, 3H), 1.44 (m, IH, H9), 1.33 (s, 3H); 13C NMR (CDC1 3 , 75 MHz) δ 137.9, 128.4, 127.8, 127.7, 111.2, 79.6, 78.2, 73.2, 70.0, 69.0, 67.6, 59.9, 46.7, 36.6, 30.2, 27.8, 26.8, 26.0, 24.7; IR (neat) 3465 (br m), 2933 (s), 2856 (m), 2789 (m), 1372 (m) cm-1 ; MS (CI, NH 3 ) m z (rel intensity) 348 [(M + H)+, 100], 256 (15), 106 (17); HRMS (CI, NH 3 ) calcd for C 20 H 29 NO 4 H [(M + H)+] 348.2175; found 348.2172; Anal. Calcd for C 20 H 29 NO 4 : C, 69.14; H, 8.41 ; N, 4.03. Found: C, 68.68; H, 8.29; N, 4.04. 305 (lS,2R,7R,8R,8aR)-7-[2-(Benzyloxy)ethyl]-l,2,8-trihydroxy-indolizidine [(7R)-7-(2- BenzyloxyethyI)-swainsonine] (305). The acetonide of the indolizidine 303 (65 mg, 0.19 mmol) was hydrolyzed with 6 N HCl in THF. Chromatography (75:25: 1 EtOAc/EtOH/Aq. NH 4 OH) provided 44 mg (80 %) as a white solid. Rf = 0.25 (50:25: 1 EtOAc/EtOH/Aq. NH40H); [α] 21 D = -59.0° (c 0.95, CH30H); IH NMR (CD30D, 360 MHz) δ 7.2-7.4 (m, 5H), 4.50 (ABq, J = 1 1.8 Hz, Dn = 15.8 Hz, 2H), 4.21 (m, IH, H2), 4.13 (dd, J = 3.6, 6.0 Hz, IH, HI), 3.97 (dd, J = 5.2, 9.9 Hz, IH, H8), 3.56 (t, J = 6.6 Hz, 2H, H10), 2.88 (dd, J = 1.9, 10.4 Hz, IH, H3), 2.69 (dt, J = 3.3, 11.6 Hz, IH, H5), 2.45 (dd, J = 7.5, 10.4 Hz, IH, H3), 2.1 (m, 2H, H5 and H7), 1.98 (m, 2H, H6), 1.52 ( , IH, H9); 1 C NMR (CD30D, 90 MHz) δ 139.9, 129.5, 129.0, 128.8, 74.0, 71.1, 70.9, 70.1, 69.4, 68.7, 63.1, 48.0, 36.9, 28.7, 26.0; IR (neat) 3380 (br s), 2942 (s), 2879 (m), 2819 (m), 1097 (s) cm-1; MS (CI, NH 3 ) m/z (rel intensity) 308 [(M + H)+, 100], 216 (33), 156 (14), 91 (19); HRMS (CI, CH 4 and NH 3 ) calcd for C, 7 H 25 N0 4 H [(M + H)+] 308.1862; found 308.1859. Example 7 Production of (lS,2R,7S,8S,8aS)-7-Butyl-l,2,8-trihydroxy-indolizidine [(7S)-7- Butylswainsonine] (332). (Z)-(2R,3S,4S)-l-tert-ButyldimethylsiIyloxy-4-hydroxy-2,3-0-isopropylidene dioxy-5- decene (315). Palladium on calcium carbonate, poisoned with lead (Lindlar's catalyst, 130 mg), and 98/14445 40 - quinoline (250 mg, 1 07 mmol), were added to solution of the diol 287 (1 17 g. 4 83 mmol) in EtOAc (22 mL) The flask was evacuated (aspirator) and purged with hydrogen three times, and the resulting heterogeneous mixture was stirred under a balloon of hydrogen After 2h, the hydrogen was evacuated, and the mixture was filtered through Cehte, πnsmg with EtOAc The filtrate was diluted with EtOAc (50 mL) and washed with 1 M HCl (2 x 25 mL), followed by saturated NaHCO, (25 mL) and bπne (25 mL) The organic layer was then dπed (MgS0 4 ), and concentrated to give 1.06 g (90% crude) of a pale yellow oil that was used without further puπfication. The crude oil was dissolved in THF/DMF (2.1, 30 mL) and die solution was cooled to 0 °C tert- Butyldimethylsilyl chloπde (0 73 g, 4.83 mmol) and imidazole (0.82 g, 13.9 mmol) were added, and the soluUon was stirred at 0°C for 2 h The mixture was then diluted with ether (100 mL), and washed with 1 M HCl (2 x 50 mL), sat. NaHC0 3 (50 mL), and bπne (50 mL) The organic layer was dπed (MgS0 4 ), and concentrated Chromatography (15:1 hex/EtOAc) provided 1 40 g (68% from the lactone 240) of the (Z)- allyhc alcohol 315 as a colorless oil Rf = 0.18 (15- 1 hex EtOAc), [α] 21 D = +15.9° (c 0.80, CHC1,), IH NMR (CDC1 3 , 300 MHz) δ 5.69 (dt, J = 7 4, 10.9 Hz, IH), 5 48 (m, IH), 4.61 (td, J = 3 1 , 8.8 Hz, IH), 4.26 (ddd, J = 3.6, 5.6, 9.5 Hz, IH), 4.11 (dd, J = 5.6, 8.9 Hz, IH), 4.00 (d, J = 3.1 Hz, IH), 3.86 (t, J = 10.2 Hz, IH), 3.67 (dd, J = 3.6, 10.5 Hz, IH), 2.14 (m, 2H), 1.37 (s, 3H), 1.32 (s. 3H), 1.3- 1.5 (m, 4H), 0.90 (m, 12H), 0.15 (s, 3H), 0.14 (s, 3H), 13C NMR (CDCl,, 75 MHz) δ 134.6, 128.8, 108.3, 80.6, 77.2, 65.3, 62.1, 31.8, 27.9, 25.9, 25.3, 22 4, 18.3, 14.0, -5.5, IR (neat) 3470 (br m), 2931 (s), 2859 (s), 1472 ( ), 1380 (m) cm-1, MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 376 [(M + NH 4 )+, 19], 359 [(M + H)+, 5], 341 (56), 283 (100), 167 (51), 151 (49), HRMS (CI, NH,) calcd for C, 9 H, 8 0 4 SιH [(M + H)+] 359.2618, found 359.2634, Anal Calcd for C l9 H 38 0 4 Sι C, 63 64, H, 10.68 Found C, 63.50, H, 10.47. Methyl E-(3S,6S,7R)-3-Butyl-8-hydroyx-6,7-0-isopropylidene-dioxy-4-octenoate (318). Tπmethyl orthoacetate (2.18 g, 18.2 mmol) and propionic acid (54 mg, 0.73 mmol) were added to a solution of the (Z)-allyhc alcohol 315 (1.40 g, 3.63 mmol) in toluene (18 mL) The flask was fitted with a distillation head, and the mixture was heated at reflux, distilling off methanol as it formed. GC was used to monitor the disappearance of starting mateπal (t R =5.2 min) and the appearance of product (t R =7.1 min, see General methods above for GC conditions) After 16 h, the mixture was cooled to room temperature and concentrated to give 1.49 g of the desired £-γ.δ-unsaturated ester as a pale yellow oil that was used without further puπfication. None of the Z-alkenyl isomer was detected by Η or π C NMR. [Purification of a small sample by chromatography (15:1 hex/EtOAc) provided an analytically pure sample of methyl (E)-(3S,6S,7R)-3-butyI-8-tert-butyldimethylsilyloxy-6,7-0-isopropyhdene-6,7-dihydroxy-4- octenoate. Rf = 0.22 (15:1 hex/EtOAc); [α] 23 D = +04° (c 1.35, CHC1 3 ); IH NMR (CDCl,. 300 MHz) d 5.59 (dd, J = 7.5, 15.5 Hz, IH), 5.50 (dd, J = 6.8, 15.5 Hz, IH), 4.54 (t, J =6.6 Hz, IH), 4.14 (dd. J = 5.9. 11.7 Hz, IH), 3.63 (s, 3H), 3.60 (m, 2H), 2.52 (m, IH), 2.36 (dd, J = 6.6, 15.0 Hz, IH). 2.30 (dd. J = 7.7, 15.0 Hz, IH), 1.47 (s, 3H), 1.35 (s, 3H), 1.2-1.4 (m, 6H), 0.90 (m, 12H), 0.07 (s, 6H), 13C NMR (CDC1 3 , 90 MHz) δ 172.6, 136.8, 126.2, 108.4, 79.0, 78.3, 62.8, 51.3, 39.9, 39.0, 34.2, 29.3, 27.9, 26.0, 25.5, 22.6, 18.4, 13.9, -5.2; IR (neat) 2930 (s), 2858 (s), 1742 (s) cm- 1 ; MS (CI. CH. and NH,) m/z (rel intensity) 432 [(M + NH 4 )+, 25], 374 (81), 357 (100), 327 (45), 207 (56); HRMS (CI. NH,) calcd for C 22 H 42 0 5 SiNH 4 [(M + NH 4 )+] 432.3145, found 423.3135; Anal Calcd for C 22 H 42 0,Sι C. 63.73, H, 10.21. Found: C, 63.76; H, 9.97.] The crude γ,δ-unsaturated ester was dissolved in THF (18 mL), tetra-n-butylammonium fluoπde (4.0 mL of a 1 M soln. in THF, 4.0 mmol) was added, and the resulung mixture was stirred at room temperature. After 1 h, the mixture was diluted with ether (100 mL) and washed with water (50 mL) and bπne (50 mL), men dried (MgS0 4 ) and concentrated. Chromatography (4: 1 to 3: 1 hex/EtOAc) provided 0.78 g (75% from 315) of the title compound as a colorless oil. The C(3) stereochemistry of 318 was deπved from analysis of the most favorable transition state for the Claisen rearrangement. Rf = 0.28 (2: 1 hex EtOAc); [α] 23 D = +26.9° (c 0.52, CHC1 3 ), IH NMR (CDCl,, 300 MHz) δ 5.66 (dd, J = 7.9, 15.5 Hz, IH), 5.52 (dd, J = 7.1, 15.5 Hz, IH), 4.64 (t, J = 6.8 Hz, IH), 4.21 (dd, J = 5.9, 12.3 Hz, IH), 3.66 (s, 3H), 3.52 (t, J = 5.9 Hz, 2H), 2.54 (m, IH), 2.41 (dd, J = 5.7, 15.2 Hz, IH), 2.33 (dd, J = 8.5, 15.2 Hz, IH), 2.11 (t, J = 6.2 Hz, IH), 1.49 (s, 3H), 1.38 (s, 3H), 1.15-1.45 (m, 6H), 0.89 (t, J = 6.9 Hz, 3H); l C NMR (CDC1 3 , 75 MHz) δ 172.9, 137.1, 125.2, 108.5, 78.4, 77.7, 62.0, 51.5, 39.6, 38.9, 34.3, 29.3, 27.9, 25.3, 22.6, 14.0; IR (neat) 3480 (br s), 2931 (s), 1737 (s) cm-1 ; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 318 [(M + NH 4 )+, 21], 243 (49), 230 (100), 207 (39); HRMS (CI, NH3) calcd for C 16 H 28 0 5 NH 4 [(M + NH 4 )+] 318.2280, found 318.2289; Anal. Calcd for C, 6 H 28 0 5 : C, 63.97; H, 9.40. Found: C, 63.43; H, 9.23. Methyl (E)-(3S,6S,7R)-8-Azido-3-butyl-6,7-0-isopropylidene-dioxy-4-octenoate (320). Hydrazoic acid (6.5 mL of a 1.2 M solution in benzene, 7.7 mmol) was added to a solution of the alcohol 318 (0.78 g, 2.6 mmol) and triphenylphosphine (1.35 g, 5.2 mmol) in benzene (13 mL). The mixture was cooled to 5°C, and diethyl azodicarboxylate (0.85 mL, 5.2 mmol) was added in a dropwise fashion. The solution was then allowed to warm to room temperature. After 2 h, TLC indicated that starting material was still present. More hydrazoic acid solution (2.2 mL, 2.6 mmol), triphenylphosphine (0.51 g, 1.9 mmol), and DEAD (0.32 mL, 1.9 mmol) were added, and the mixture was allowed to stir at room temperature for another 1 h. The mixture was then poured into hexanes (100 mL), resulting in the formation of a white precipitate. The mixture was filtered and the filtrate was concentrated. Chromatography (15:1 to 10:1 hexane/EtOAc) provided 0.645 g (77%) of the azide 320 as a colorless oil. Rf = 0.23 (8: 1 hex/EtOAc); [α] 23 D = +56.3° (c 0.86, CHC1 3 ); IH NMR (CDC1 3 , 300 MHz) δ 5.68 (dd, J = 8.2, 15.5 Hz, IH), 5.44 (dd, J = 7.4, 15.4 Hz, IH), 4.62 (t, J = 6.9 Hz, IH), 4.26 (ddd, J = 4.2, 6.6, 7.8 Hz, IH), 3.66 (s, 3H), 3.27 (dd, J = 7.8, 12.8 Hz, IH), 3.13 (dd, J = 4.2, 12.8 Hz, IH), 2.57 (m, IH), 2.39 (dd, J = 6.1, 15.0 Hz, IH), 2.32 (dd, J = 8.1, 15.0 Hz, IH), 1.52 (s, 3H), 1.39 (s, 3H), 1.15-1.45 (m, 6H), 0.89 (t, J = 6.8 Hz, 3H); 13 C NMR (CDC1 3 , 75 MHz) δ 172.5, 137.9, 124.7, 109.1, 77.8, 77.0, 51.7, 51.4, 39.6, 38.9, 34.2, 29.3, 27.9, 25.4, 22.6, 14.0; IR (neat) 2932 (m), 2102 (s), 1738 (s) cm-1; MS (CI, NH 3 ) m/z (rel intensity) 343 [(M + NH 4 )+, 9], 298 (97), 268 (100), 240 (20); HRMS (CI, NH 3 ) calcd for C 16 H 27 N 3 0 4 NH 4 [(M + NH 4 )+] 343.2345; found 343.2331; Anal. Calcd for C 16 H 27 N 3 0 4 : C, 59.06; H, 8.36; N, 12.91. Found: C, 59.43; H, 8.35; N, 12.86. Methyl (3S,4R,5S,6R,7R)-8-Azido-3-butyl-4,5-epoxy-6,7-0- isopropylidenedioxyoctanoate (322α) and Methyl (3S,4S,5R,6R,7R)-8-Azido-3-butyl- 4,5-epoxy-6,7-0-isopropylidene-dioxyoctanoate (322β). m-Chloroperbenzoic acid (1.05 g, technical grade, 0.84 g pure, 4.9 mmol) was added to a cooled (0°C) solution of the azide 320 (0.63 g, 1.9 mmol) in CH 2 C1 2 (10 mL). After 24 h, the mixture was diluted with ether (50 mL) and washed with 1 M NaOH (2 x 25 mL). The aqueous layers were back-extracted with ether (2 x 25 mL), and the combined organic layers were washed with saturated NaHC0 3 (50 mL) and brine (25 mL), then dried (MgS0 4 ), filtered, and concentrated to provide 0.64 g (96% cmde) of a mixture (2: 1 by IH NMR integration) of diastereomeric epoxides 322α and 322β that were used without futher purification. Purification of a small sample by chromatography (20: 1 to 15:1 hex/EtOAc gradient) provided analytically pure samples of the epoxides 322α and 322β. The stereochemistry of these epoxides was assigned based on spectral comparison to epoxides 252α and 252β and by subsequent conversion to lactams 324 and 325 (see below) Data for 322α: Rf = 0.29 [8:1 hex/EtOAc (2 elutions)]; [α] 23 D = +57.7° (c 0.65, CHC1 3 ); IH NMR (CDC1 3 , 360 MHz) δ 4.34 (td, J = 4.3, 6.7 Hz, IH), 3.68 (s, 3H), 3.65 (dd, J = 6.4, 8.1 Hz, IH), 3.59 (dd, J = 4.3, 13.1 Hz, IH), 3.53 (dd, J = 6.9, 13.1 Hz, IH), 2.86 (dd, J = 2.0, 8.2 Hz, IH), 2.74 (dd, J = 2.0, 7.7 Hz, IH), 2.39 (dd, J = 6.5, 15.6 Hz, IH), 2.31 (dd, J = 7.6, 15.6 Hz, IH), 1.85 (m, IH), 1.52 (s, 3H), 1.37 (s, 3H), 1.25-1.55 (m, 6H), 0.90 (t, J = 6.9 Hz, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 172.2, 109.5, 77.3, 76.3, 60.8, 53.7, 51.3, 50.1, 36.8, 35.3, 31.8, 28.4, 27.3, 24.7, 22.4, 13.6; IR (neat) 2934 (m), 2102 (s), 1738 (s) cm-1 ; MS (CI, NH 3 ) m/z (rel intensity) 359 [(M + NH 4 )+, 7], 342 [(M + H)+, 73], 314 (100), 256 (38), 142 (39); HRMS (CI, NH 3 ) calcd for C 16 H 27 N 3 0 5 H [(M + H)+] 342.2029; found 342.2041; Anal. Calcd for C 16 H 27 N 3 0 5 : C, 56.29; H, 7.97; N, 12.31. Found: C, 56.63; H, 7.96; N, 12.38. Data for 322β: Rf = 0.23 [8: 1 hex/EtOAc (2 elutions)]; [α] 23 D = +2.2° (c 0.45, CHC1 3 ); IH NMR (CDC1 3 , 360 MHz) δ 4.36 (td, J = 5.2, 6.9 Hz, IH), 4.10 (dd, J = 3.9, 6.6 Hz, IH), 3.68 (s, 3H), 3.58 (dd, J = 7.1, 12.7 Hz, IH), 3.47 (dd, J = 5.2, 12.7 Hz, IH), 2.88 (m, 2H), 2.45 (dd, J = 6.5, 15.5 Hz, IH), 2.34 (dd, J = 6.7, 15.5 Hz, IH), 1.86 (q, J = 6.7 Hz, IH), 1.48 (s, 3H), 1.35 (s, 3H), 1.25-1.55 (m, 6H), 0.90 (t, J = 6.9 Hz, 3H); 13C NMR (CDC1 3 , 90 MHz) δ 172.9, 109.7, 76.6, 76.0, 57.1, 55.7, 51.6, 51.1, 37.2, 35.9, 31.0, 29.2, 27.0, 25.2, 22.7, 13.9; IR (neat) 2934 (m), 2103 (s), 1738 (s) cm-1; MS (CI, NH 3 ) m/z (rel intensity) 359 [(M + NH4)+, 31], 342 [(M + H)+, 46], 314 (100), 282 (48), 158 (90), 142 (83); HRMS (CI, CH 4 and NH 3 ) calcd for C 16 H 27 N 3 0 5 H [(M + H)+] 342.2029; found 342.2034; Anal. Calcd for C 16 H 27 N 3 0 5 : C, 56.29; H, 7.97; N, 12.31. Found: C, 56.55; H, 7.99; N, 11.92. (lS,2R,7S,8S,8aS)-7-Butyl-8-hydroxy-l,2-0-isopropyIidene-dioxyindolizidin-5-one (325) and (lS,2R,7S,8R,8aR)-7-Butyl-8-hydroxy-l,2-0-isopropylidenedioxy- indolizidin-5-one (324). Palladium hydroxide on carbon (90 mg) was added to a solution of the mixture of epoxides 322αβ (2: 1, 580 mg, 1.7 mmol) in MeOH/EtOAc (1: 1, 25 mL). The flask was evacuated (aspirator) and purged with hydrogen three times, and the resulting heterogeneous mixture was stirred under a balloon of hydrogen. After 3 h, the hydrogen was evacuated, the mixture was filtered, and the filtrate was concentrated. The residue was dissolved in MeOH (25 mL), sodium methoxide (46 mg, 0.9 mmol) was added, and the mixture was warmed to reflux. Reaction progress was monitored by IR for the disappearance of the ester and lactone carbonyl stretches at 1735 cm-1 and 1775 cm-1 and appearance of the lactam carbonyl stretch at 1630 cm-1. After 48 h, the mixture was cooled to room temperature and concentrated. The residue was dissolved in CH 2 Cl 2 /MeOH (20:1, 10 mL), Florisil (1 g) was added, and die mixture was stirred for 15 min. The suspension was then filtered through Celite, and the filtrate was concentrated. Chromatography (100: 1 to 50: 1 CH 2 Cl 2 /MeOH) provided 290 mg (60%) of a mixture (1:2.4 by IH NMR integration) of the lactams 325 and 324. The stereochemistry of 324 and 325 was assigned based on spectral comparison to 222 and 253. Rf = 0.31 (20:1 CHCl 3 /MeOH); IH NMR (CDC1 3 , 300 MHz, α indicates major isomer and β indicates minor isomer, α/β ratio ~ 2.4: 1 ) δ 4.81 (dd, J = 4.5, 6.0 Hz, lHα), 4.75 (t, J = 6.0 Hz, lHα), 4.72 (td, J = 2.9, 6.6 Hz, lHβ), 4.40 (t, J = 6.8 Hz, lHβ), 4.31 (dd, J = 6.6, 13.5 Hz, lHβ), 4.17 (d, J = 13.6 Hz, lHα), 3.90 (dt, J = 3.9, 7.6 Hz, lHβ), 3.75 (ddd, J = 5.0, 8.9, 10.3 Hz, lHα), 3.40 (t, J = 7.1 Hz, lHβ), 3.32 (dd, J = 4.2, 8.8 Hz, lHα), 3.31 (dd, J = 2.9, 13.5 Hz, lHβ), 3.34 (dd, J = 4.7, 13.7 Hz, lHα), 2.61 (m, 2Hα +lHβ), 2.48 (dd, J = 4.5, 17.5 Hz, lHβ), 2.31 (dd, J = 5.2, 17.5 Hz, lHβ), 2.03 (dd, J = 11.9, 17.1 Hz, lHα), 1.7-1.9 (m, 2Hα + 2Hβ) , 1.57 (s, 3Hβ), 1.42 (s, 3Hα), 1.37 (s, 3Hβ), 1.34 (s, 3Hα), 1.1-1.5 (m, 6Hα + 6Hβ), 0.90 (t, J = 6.9 Hz, 3Hα + 3Hβ); 13C NMR (CDC1 3 , 90 MHz, α indicates major isomer and β indicates minor isomer) δ 168.2, 112.1, 83.6 (β), 79.8 (α), 77.7 (α), 76.9 (β), 70.8 (β), 69.4 (α), 65.9 (α), 64.9 (β), 50.5 (α), 50.0 (β), 39.4 (α), 37.6 (β), 36.0 (α), 34.3 (β), 31.0 (α), 29.6 (β), 28.2 (α), 27.7 (β), 27.1 (β), 26.5 (α), 25.5 ( β), 24.8 (α), 22.8 (α), 14.0; IR (neat) 3360 (br m), 2934 (m), 1633 (s) cm-1; MS (CI, NH 3 ) m/z (rel intensity) 284 [(M + H)+, 100], 208 (2); HRMS (CI, CH 4 ) calcd for C 15 H 25 N0 4 H [(M + H)+] 284.1862; found 284.1875; Anal. Calcd for C„H 2 N0 4 : C, 63.58; H, 8.89; N, 4.94. Found: C. 63.22: H. 8.86: N. 4.91. (lS,2R,7S,8R,8aR)-7-Butyl-8-hydroxy-l,2-0-isopropylidene-dioxyindolizidine (328) and (lS,2R,7S,8S,8aS)-7-Butyl-8-hydroxy-l,2-0-isopropylidenedi oxy indolizidine (329) Reduction of the mixture of lactams 324 and 325 (2.4: 1 , 280 mg, 0.99 mmol) was carried out with borane-methyl sulfide complex. Chromatography (100:1 to 50:1 CH Cl 2 /MeOH gradient) provided 155 mg (58%) of the indolizidine 328 as a white crystalline solid followed by 59 mg (22%) of the indolizidine 329 as a pale yellow oil. Data for 328 (major): Rf = 0.35 (20:1 CHCl 3 /MeOH); [α] 23 D = -26.4° (c 0.70, CHC1,); mp 96 °C; IH NMR (CDC1 3 , 300 MHz) δ 4.69 (dd, J = 4.5, 6.2 Hz, IH, HI), 4.61 (dd, J = 4.2, 6.2 Hz, IH, H2), 3.48 (td, J = 4.7, 9.0 Hz, IH, H8), 3.13 (d, J = 10.7 Hz, IH, H3eq), 3.00 (m, IH, H5eq), 2.13 (d, J = 4.6 Hz, IH, HOH), 2.10 (dd, J = 4.2, 6.4 Hz, IH, H3ax), 1.75-1.95 (m, 3H), 1.67 (dd, J = 4.4, 8.9 Hz, IH, H8a), 1.51 (s, 3H), 1.32 (s, 3H), 1.05-1.45 (m, 7H), 0.90 (t, J = 6.9 Hz, 3H, H12); 13 C NMR (CDCl,, 75 MHz) δ 111.2, 79.3, 78.6, 73.4, 71.4, 59.9, 51.7, 43.0, 31.5, 29.9, 29.0, 26.1 , 24.9, 23.1 , 14.1 ; IR (neat) 3290 (br m), 2918 (s), 2858 (m), 2793 (m), 1466 (m) cm- 1 ; MS (CI, NH 3 ) m/z (rel intensity) 270 [(M + H)+, 100], 252 (39), 194 (21); HRMS (CI, NH 3 ) calcd for C l5 H 27 N0 3 H [(M + H)+] 270.2069; found 270.2061; Anal. Calcd for C 15 H 27 N0 3 : C, 66.88; H, 10.10; N, 5.20. Found: C, 66.78; H, 10.35; N, 5.27. Data for 329 (minor): Rf = 0.29 (20:1 CHCl 3 /MeOH); IH NMR (CDC1 3 , 300 MHz) δ 4.70 (td, J = 5.1, 6.6 Hz, IH, H2), 4.41 (dd, J = 6.1, 7.1 Hz, IH, HI), 3.63 (dd, J = 5.0, 9.6 Hz, IH, H8), 3.37 (dd, J = 6.4, 9.4 Hz, IH, H3eq), 2.62 (ddd, J = 2.8, 4.3, 11.3 Hz, IH, H5eq), 2.43 (dd, J = 5.0, 9.4 Hz, IH, H3ax), 2.38 (td, J = 3.4, 11.4 Hz, IH, H5ax), 2.23 (dd, J = 6.0, 9.7 Hz, IH, H8a), 1.95 (m, IH, HOH), 1.45-1.75 (m, 3H), 1.52 (s, 3H), 1.34 (s, 3H), 1.1-1.45 (m, 5H), 0.91 (t, J = 7.1 Hz, 3H, HI 2); ,3 C NMR (CDCl,, 75 MHz) δ 114.4, 83.5, 77.6, 73.7, 68.3, 59.4, 45.9, 38.6, 30.3, 27.1, 26.8, 24.9, 23.5, 23.0, 14.1 ; IR (neat) 3465 (br m), 2931 (s), 2869 (m), 2803 (m) 1456 (m), 1372 (m) cm-1; MS (CI, CH 4 and NH 3 ) m z (rel intensity) 270 [(M + H)+, 100], 252 (17); HRMS (CI, CH 4 and NH 3 ) calcd for C 15 H 27 N0 3 H [(M + H)+] 2702069, found 270.2061 Example 8 Production of (lS,2R,7S,8S,8aS)-7-Butyl-l,2,8-trihydroxy-indolizidine [(7S)-7- Butylswainsonine] (332). 332 The acetonide of the indolizidine 328 (110 mg, 0 41 mmol) was hydrolyzed with 6 N HCl in THF Recrystallization from EtOAc provided 73 mg (78%) of the title compound Rf = 0 37 (50.25.1 EtOAc/EtOH/Aq NH40H); [α] 23 D = -22.6° (c 1.05, MeOH), mp 1 15 °C, IH NMR (CDCl,, 360 MHz) δ 4.25 (m, 2H), 3 4-4.2 (br m, 3H, D20 exchangeable), 3.48 (t, J = 9.3 Hz, IH), 2 98 (m, 2H), 2 38 (dd, J = 6.5, 10.7 Hz, IH), 1.9 (m, 2H), 1.80 (m, 2H), 1.0-1 45 (m, 7H), 0.90 (t, J = 7 0 Hz, 3H), 13 C NMR (CDC1 3 , 90 MHz) δ 73.5, 70.7, 70.2, 69.6, 62.1 , 52.1, 42.6, 31 4, 29.3, 29.0, 23.0, 14 1 , IR (neat) 3380 (br m), 2949 (s), 2813 (m) cm-1, MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 230 [(M + H)+, 91], 212 (100), 194 (29), 176 (19), HRMS (CI, CH 4 and NH,) calcd for C I2 H 2 ,NO,H [(M + H)+] 230 1756, found 230.1760; Anal. Calcd for C 12 H 23 N0 3 : C, 62.84, H, 10 11 , N, 6.1 1 Found- C, 62 49, H, 10 01 , N, 6.06. Example 9 Production of (lS,2R,7S,8S,8aS)-7-ButyI-l,2,8-trihydroxy-indolizidine [(7S)-7-Butyl- 8,8a-diepiswainsonine] (334) 334 The acetonide of the indolizidine 329 (35 mg, 0.13 mmol) was hydrolyzed with 6 N HCl in THF using the procedure described above for preparation of 304. Chromatography (75:25: 1 EtOAc/EtOH/Aq. NH40H) provided 24 mg (80%) of the title compound as a pale yellow oil Rf = 0 12 (75.25 1 EtOAc/EtOH/Aq NH40H), [αf D = +2.5° (c 043, MeOH), mp 120 °C, IH NMR (CDCl,. 360 MHz) δ 4 21 (td. J = 4 8. 6 7 Hz, IH), 3.86 (t, J = 7.6 Hz, IH), 3 72 (dd, J = 4.9, 9.0 Hz, IH), 3 46 (dd. J = 6 6. 10.2 Hz. IH). 3 3- 3.7 (br m, 3H, D20 exchangeable), 2.63 (dt, J = 3.6, 10.9 Hz, IH), 2.32 (m, 2H), 2 19 (t, J = 8 6 Hz, IH), 1.89 (m, IH), 1.72 (m, IH), 1.60 (m, 2H), 1.15-1 45 (m, 5H), 0.91 (t, J = 7 0 Hz, 3H), π C NMR (CDC1 3 , 90 MHz) δ 74.8, 74.2, 67.4, 65.5, 61.3, 46.6, 38.3, 30.2, 26.8, 23.9. 23 0, 14 1 , IR (neat) 3370 (br s), 2930 (s), 2870 (m), 1124 (m) cm-1, MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 230 [(M + H)+, 100], 212 (91), 194 (16), HRMS (CI, CH 4 and NH,) calcd for C I2 H 2 ,NO,H [(M + H)+] 230 1756. found 230.1766. Example 1 Production of ( lS,2R,7S,8R,8aR)-7-[2-(Benzyloxy)ethyl]-l,2,8-trihydroxyindolizidine [(7S)-7-(2-Benzyloxyethyl)swainsonine] (333). (Z)-(5S,6S,7R)-l-Benzyloxy-8-tert-butyldimethylsilyloxy5-hydroxy-2,3-0- isopropyIidene-dioxy-3-octene (316). Palladium on calcium carbonate, poisoned with lead (L dlar's catalyst, 120 mg) and quinohne (97 mg, 0.75 mmol) were added to solution of the diol 288 (1.22 g, 3.75 mmol) in EtOAc (12 mL). The flask was evacuated (aspirator) and purged with hydrogen three times, and the resulting heterogeneous mixture was stirred under a balloon of hydrogen After 3 h, the hydrogen was evacuated, and the mixture was filtered through Celite, πnsing with EtOAc The filtrate was diluted with EtOAc (50 mL) and washed with 1 M HCl (2 x 25 mL), followed by saturated NaHCO, (25 mL) and bπne (25 mL). The organic layer was then dπed (MgS0 4 ), and concentrated to give 1.09 g (90% crude) of a pale yellow oil that was used without further puπfication [A small sample was puπfied by chromatography (2:1 hex/EtOAc) to provide an analytically pure sample of (Z)-(5S,6S,7R)-l-Benzyloxy- 2,3-0-ιsopropyhdene-l,2,3,4-tetrahydroxy-3-octene. Rf = 0.31 (2:1 hex/EtOAc - 3 elutions), [α] 23 D = +26.3° (c 0.85, CHC1 3 ), IH NMR (CDC1 3 , 300 MHz) δ 7.2-7 4 (m, 5H), 5.80 (dd, J = 7.1, 1 1.0 Hz, IH), 5.72 (m, IH), 4.51 (m, 3H), 4.33 (ddd, J = 4.8, 5.7, 8.3 Hz, IH), 4.10 (dd, J = 5.8, 9.0 Hz, IH), 3.85 (ddd, J = 4.5, 8.3, 11.6 Hz, IH), 3.82 (d, J = 1.9 Hz, IH), 3.72 (ddd, J = 4.7, 9.0, 1 1.6 Hz, IH), 3.62 (dt, J = 4.5, 8.7 Hz, IH), 3.45 (m, 2H), 2.66 (m, IH), 2.29 (m, IH), 1.38 (s, 3H), 1.34 (s, 3H); 13 C NMR (CDC1 3 , 75 MHz) δ 137.1, 132 7, 130 9, 128.5, 128 0, 127 9, 108 3, 79 4. 77 6. 73.5. 68 5. 64 8. 60 9. 28 7, 27.8, 25.3, IR (neat) 3385 (br s), 2985 (m), 2934 (s), 2866 (s). 1370 (m) cm- 1. MS (CI. NH,) m/z (rel intensity) 340 [(M + NH 4 )+, 15], 322 [M+, 89], 305 (100), 282 (77), 247 (60), 106 (62). HRMS (CI. NH 3 ) calcd for C lg H 26 0 5 NH 4 [(M + NH 4 )+] 340.2124, found 340.2109, Anal Calcd for C, 8 H 2 0, C, 67.06; H, 8.13 Found. C, 66.91 , H, 8.06.] The crude (Z)-alkenyl diol was dissolved in THF/DMF (2: 1, 15 mL) and the solution was cooled to 0°C tert-Butyldimethylsilyl chloπde (0.58 g, 3.8 mmol) and lmidazole (0.57 g, 8.3 mmol) were added and the solution was sϋrred at 0 °C for 2 h The mixture was tiien diluted with ether (100 mL), and washed with 1 M HCl (2 x 50 mL), sat. NaHC0 3 (50 mL), and brine (50 mL) The organic layer was dned (MgS0 4 ) and concentrated Chromatography (10.1 hex/EtOAc) provided 1.09 g (70% from the lactone 240) of the (ZV allyhc alcohol 316 as a colorless oil. Rf = 0.66 (2- 1 hex EtOAc), [α] 23 D = +15 4° (c 0 90, CHC1,), IH NMR (CDC1 3 , 300 MHz) δ 7.2-7 4 (m, 5H), 5.71 (dt, J = 7.2, 1 1.0 Hz, IH), 5 60 (dd J = 8.1 , 1 1 0 Hz, IH), 4.61 (td, J = 2.8, 8.2 Hz, IH), 4.51 (s, 2H), 4.25 (ddd J = 3 9, 5.6, 9.2 Hz, IH), 4 1 1 (dd, J = 5 7, 8.9 Hz, IH), 4.04 (d, J = 2.9 Hz, IH), 3.87 (t, J = 10.0 Hz, IH), 3.67 (dd, J = 3.8, 10.6 Hz, IH), 3.54 (m, 2H), 2.51 (m, 2H), 1.35 (s, 3H), 1.31 (s, 3H), 0.92 (s, 9H), 0.14 (s, 6H), 13 C NMR (CDCl,, 75 MHz) δ 138.3, 131.0, 129.9, 128.2, 127.5, 127 4, 108.3, 80.2, 77.2, 72.9, 69.7, 65.3, 62.0, 28.9, 27.9, 25.8, 25.2, 18.2, -5.5, IR (neat) 3460 (br m), 2933 (s), 2857 (s) 1362 (s) cm-1 , MS (CI, NH,) m/z (rel intensity) 454 [(M + NH 4 )+, 3], 437 [(M + H)+, 12], 419 (82), 396 (67), 379 (100), 361 (59), 222 (97), HRMS (CI, NH 3 ) calcd for C^H^H [(M + H)+] 437.2723 found 437.2692, Anal Calcd for C 24 H 4n O,Sι C, 66.02; H, 9.23 Found: C, 65.99; H, 9.05. Methyl (E)-(3S,6S,7R)-3-[2-(Benzyloxy)ethyl]-l-tert-butyl-dimethylsilyioxy-6,7-0- isopropylidene-dioxy-4-octenoate. Tπmethyl orthoacetate (1.40 g, 11.6 mmol) and propionic acid (35 mg, 0 46 mmol) were added to a solution of the (Z)-allyhc alcohol 316 (1.01 g, 2.31 mmol) in toluene (10 mL) The flask was fitted with a distillation head and die mixture was heated at reflux, distilling off methanol as it formed. After 16 h, the mixture was cooled to room temperature and concentrated Chromatography (10: 1 to 8: 1 hex/EtOAc gradient) provided 0.860 g (75%) of the E-γ,δ-unsaturated ester as a colorless oil None of the Z-alkenyl isomer was detected by IH or 13C NMR. The C(3) stereochemistry of the E-7,δ-unsaturated ester was deπved from analysis of the most favorable transition state for the Claisen rearrangement Rf = 0.63 (2: 1 hex EtOAc); [α] 23 D = -12.9° (c 1.15, CHC1 3 ); IH NMR (CDC1 3 , 360 MHz) δ 7.2-7.4 (m, 5H), 5.64 (dd a , < . Λ m * 98/14445 - 49 - J = 8.2, 15.4 Hz, IH), 5.52 (dd, J = 6.7, 15.4 Hz, IH), 4.55 (t, J = 6.7 Hz. IH). 4.47 (t, J = 12.2 Hz. 2H). 4.14 (dd, J = 5.9, 12.2 Hz, IH), 3.64 (s, 3H), 3.58 (d, J = 5.8 Hz, 2H), 3.48 (m. 2H). 2.77 (m. IH). 2.41 (dd, J = 6.6, 15.1 Hz, IH), 2.35 (dd, J = 7.6, 15.1 Hz, IH), 1.78 (m, IH), 1.62 (m, IH). 1.46 (s. 3H). 1.35 (s, 3H), 0.89 (s, 9H), 0.06 (s, 6H); 13C NMR (CDC1 3 , 90 MHz) δ 172.5, 138.4, 135.9, 128.3, 127.5, 127.4, 126.5, 108.4, 78.7, 77.9, 72.8, 67.9, 62.6, 51.4, 39.6, 35.9, 34.1 , 27.8. 25.9, 25.3, 18.2, -5.3; IR (neat) 2930 (s), 2856 (s), 1739 (s) cm-1 ; MS (CI, NH 3 ) m/z (rel intensity) 510 [(M + NH 4 )+, 100], 435 (37), 327 (26), 195 (76); HRMS (CI, NH 3 ) calcd for C^H^O.SiNH, [(M + NH 4 )+] 510.3251, found 510.3271; Anal. Calcd for C^H^Si: C, 65.82; H, 9.00. Found: C, 65.52; H, 8.88. Methyl (E)-(3S,6S,7R)-3-[2-(Benzyloxy)ethyl]-8-hydroxy-6,7-0-isopropylidenedioxy-4- octenoate (319). Tetra-n-butylammonium fluoride (1.9 mL of a 1 M soln. in THF, 1.9 mmol) was added to a solution of the E-γ,δ-unsaturated ester (0.84 g, 1.70 mmol) in THF (9 mL), and the resulting mixture was stirred at room temperature. After 1 h, the mixture was diluted with ether (50 mL), and washed with water (25 mL), and brine (25 mL), then dried (MgS0 4 ), and concentrated. Chromatography (2: 1 hex/EtOAc) provided 0.60 g (93%) of the alcohol 319 as a colorless oil. Rf = 0.10 (2: 1 hex/EtOAc); [α ] 23 D = +6.3° (c 0.80, CHC1 3 ); IH NMR (CDC1 3 , 360 MHz) δ 7.2-7.4 (m, 5H), 5.66 (dd, J = 8.4, 15.5 Hz, IH), 5.53 (dd, J = 6.7, 15.5 Hz, IH), 4.60 (t, J = 6.7 Hz, IH), 4.47 (ABq, J = 12.0 Hz, Dn = 14.2 Hz, 2H), 4.18 (dd, J = 6.0, 12.1 Hz, IH), 3.65 (s, 3H), 3.47 (m, 4H), 2.77 (m, IH), 2.45 (dd, J = 5.7, 15.5 Hz, IH), 2.36 (dd,J = 8.5, 15.5 Hz, IH), 2.15 (dd, J = 6.0, 6.7 Hz, IH), 1.76 (m, IH), 1.62 (m, IH), 1.47 (s, 3H), 1.37 (s, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 172.8, 138.3, 136.1, 128.3, 127.7, 127.6, 125.7, 108.5, 78.2, 77.4, 72.9, 67.7, 61.7, 51.6, 39.3, 36.0, 34.2, 27.8, 25.2; IR (neat) 3488 (m), 2934 (s), 2868 (s), 1736 (s) cm-1 ; MS (CI, NH 3 ) m/z (rel intensity) 396 [(M + NH 4 )+, 48], 321 (64), 303 (58), 213 (70), 195 (100); HRMS (CI, NH 3 ) calcd for C 21 H 30 O 6 NH 4 [(M + NH 4 )+] 396.2386, found 396.2368. Methyl (E)-(3S,6S,7R)-8-Azido-3-[2-(benzyloxy)ethyl]-6,7-0-isopropylidene dioxy-4- octenoate (321). Hydrazoic acid (3.6 mL of a 1.2 M solution in benzene, 4.4 mmol) was added to a solution of the alcohol 319 (0.55 g, 1.5 mmol) and triphenylphosphine (0.76 g, 2.9 mmol) in benzene (7.5 mL). The mixture was cooled to 5 °C and diethyl azodicarboxylate (0.48 mL, 2.9 mmol) was added in a dropwise fashion. The solution was then allowed to warm to room temperature. After 2 h, TLC indicated that starting material was still present. More hydrazoic acid solution (1.2 mL, 1.4 mmol), triphenylphosphine (0.29 g, 1.1 mmol), and DEAD (0.18 mL, 1.1 mmol) were added and the mixture was allowed to stir at room temperature for another 1 h. The mixture was then poured into hexanes (50 mL), resulting in the formation of a white precipitate. The mixture was filtered, and the filtrate was concentrated. Chromatography (8: 1 to 6:1 hexane/EtOAc) provided 0.465 g (80%) of the azide 321 as a colorless oil. Rf = 0.15 (6: 1 hex/EtOAc); [α] 23 D = +22.3° (c 0.90, CHC1 3 ); IH NMR (CDC1 3 , 360 MHz) δ 7.2-7.4 (m, 5H), 5.68 (dd, J = 8.4, 15.5 Hz, IH), 5.43 (dd, J = 7.2, 15.5 Hz, IH), 4.58 (t, J = 6.9 Hz, IH), 4.47 (ABq, J = 12.0 Hz, Dn = 17.2 Hz, 2H), 4.22 (ddd J = 4.2, 6.8, 7.8 Hz, IH), 3.65 (s, 3H), 3.45 (m, 2H), 3.18 (dd, J = 7.9, 12.8 Hz, IH), 3.05 (dd, J = 4.2, 12.8 Hz, IH), 2.79 (m, IH), 2.44 (dd, J = 6.0, 15.2 Hz, IH), 2.35 (dd, J = 8.2, 15.2 Hz, IH), 1.77 (m, IH), 1.63 (m, IH), 1.51 (s, 3H), 1.37 (s, 3H); 13 C NMR (CDC1 3 , 90 MHz) δ 172.4, 138.3, 137.1, 128.4, 127.6, 125.1, 109.1, 77.5, 76.9, 72.9, 67.7, 51.5, 39.4, 36.0, 34.2, 27.8, 25.2; IR (neat) 2987 (m), 2934 (m), 2861 (m), 2101 (s), 1738 (s) cm-1 ; MS (CI, NH 3 ) m/z (rel intensity) 421 [(M + NH 4 )+, 7], 376 (100), 318 (22); HRMS (CI, NH 3 ) calcd for C 21 H 29 N 3 0 5 NH 4 [(M + NH4)+] 421.2451; found 421.2462; Anal. Calcd for C 21 H 29 N 3 0 5 : C, 62.51 ; H, 7.24; N, 10.41. Found: C, 62.47; H, 7.25; N, 10.46. Methyl (3S,4R,5S,6R,7R)-8-Azido-3-[2-(benzyloxy)ethyl]-4,5-epoxy-6,7-0- isopropylidene-dioxyoctanoate (323α) and Methyl (3S,4S,5R,6R,7R)-8-Azido-3-[2- (benzyloxy)ethyI]-4,5-epoxy-6,7-0-isopropylidenedioxyoctanoate (323β). m- Chloroperbenzoic acid (0.56 g, technical grade, 0.45 g pure, 3.1 mmol) was added to a cooled (0 °C) solution of the azide 321 (0.42 g, 1.0 mmol) in CH 2 C1 2 (5 mL). After 24 h, the mixture was diluted with ether (50 mL) and washed with 1 M NaOH (2 x 25 mL). The aqueous layers were back-extracted with ether (2 x 25 mL), and the combined organic layers were washed with saturated NaHC0 3 (25 mL) and brine (25 mL), then dried (MgS0 4 ), and concentrated. Chromatography (6:1 hex/EtOAc) provided 325 mg (75%) of a mixture (1.7: 1 by IH NMR integration) of epoxides 323a and 323b. The stereochemistry of these epoxides was assigned based on spectral comparison with epoxides 252α and 252β (see above) and by subsequent conversion to lactams 326 and 327. Data for 323α/β : Rf = 0.28 (4: 1 hex/EtOAc); IH NMR (CDC1 3 , 360 MHz) major isomer (α) δ 7.2-7.4 (m, 5H), 4.50 (s, 2H), 4.34 (td, J = 4.4, 6.7 Hz, IH), 3.67 (s, 3H), 3.66 (dd, J = 6.4, 7.9 Hz, IH), 3.56 (m, 4H), 2.83 (m, 2H), 2.46 (dd, J = 6.3, 15.8 Hz, IH), 2.37 (dd, J = 7.7, 15.8 Hz, IH), 2.02 (m, IH), 1.7-1.9 (m, 2H), 1.50 (s, 3H), 1.34 (s, 3H); minor isomer (β) δ 7.2-7.4 (m, 5H), 4.47 (ABq, J = 12.2 Hz, Dn = 19.6 Hz, 2H), 4.19 (td, J = 5.1, 6.8 Hz, IH), 3.87 (dd, J = 4.2, 6.7 Hz, IH), 3.66 (s, 3H), 3.52 (m, 3H), 3.39 (dd, J = 5.0, 12.7 Hz, IH), 2.90 (dd, J = 2.2, 7.5 Hz, IH), 2.80 (dd, J = 2.2, 4.2 Hz, IH), 2.50 (dd, J = 6.2, 15.6 Hz, IH), 2.39 (dd, J = 7.0, 15.6 Hz, IH), 2.01 (m, IH), 1.77 (m, 2H), 1.44 (s, 3H), 1.35 (s, 3H); 13 C NMR (CDC1 3 , 90 MHz) major isomer (α) δ 172.1, 138.3, 128.2, 127.5, 127.4, 109.8, 77.5, 76.6, 73.0, 67.9, 60.8, 54.2, 51.6, 50.6, 35.7, 34.9, 32.2, 27.6, 25.1; minor isomer (β) δ 172.5, 138.1, 128.3, 127.8, 127.7, 109.6, 76.0, 75.9, 73.1, 67.7, 57.0, 55.8, 51.6, 51.2, 35.9, 35.2, 31.1, 27.1, 25.2; IR (neat) 2988 (m), 2937 (m), 2863 (m), 2102 (s), 1738 (s) cm-1; MS (CI, NH 3 ) m/z (rel intensity) 437 [(M + NH 4 )+, 28], 392 (76), 360 (57), 142 (100), 108 (54); HRMS (CI, NH 3 ) calcd for C 21 H 29 N 3 0 6 NH 4 [(M + NH 4 )+] 437.2400; found 437.2397; Anal. Calcd for C 21 H 29 N 3 0 6 : C, 60.13; H, 6.97; N, 10.02. Found: C, 60.30; H, 7.07; N, 10.00. (lS,2R,7S,8S,8aS)-7-[2-(Benzyloxy)ethyl]-8-hydroxy-l,2-0-isopropylidenedi oxyindolizidin-5-one (326) and (lS,2R,7S,8R,8aR)-7-[2-(Benzyloxy)ethyl]-8-hydroxy- l,2-0-isopropylidenedioxy-indoIizidin-5-one (327). Palladium hydroxide on carbon (50 mg) was added to a solution of the mixture of the epoxides 323αβ (1.7: 1 , 325 mg, 0.78 mmol) in MeOH/EtOAc (1 : 1 , 12 mL). The flask was evacuated (aspirator) and purged with hydrogen three times, and the resulting heterogeneous mixture was stirred under a balloon of hydrogen. After 3 h, the hydrogen was evacuated, the mixture was filtered, and the filtrate was concentrated. The residue was dissolved in MeOH (12 mL), sodium methoxide (21 mg, 0.38 mmol) was added and die mixture was warmed to reflux. Reaction progress was monitored by IR for the disappearance of the ester and lactone carbonyl stretches at 1730 cm-1 and 1780 cm "1 and appearance of the lactam carbonyl stretch at 1625 cm "1 . After 48 h, the mixture was cooled to room temperature and concentrated. The residue was dissolved in CH 2 Cl 2 /MeOH (20: 1, 10 mL), Florisil (1 g) was added, and the mixture was stirred for 15 min. The suspension was then filtered through Celite and the filtrate was concentrated. Chromatography (100: 1 to 75: 1 CH 2 Cl 2 /MeOH) provided 250 mg (89%) of a mixture (1.7: 1 based on IH NMR integration) of the the lactams 326 and 327 as a colorless oil. The stereochemistry of these epoxides was assigned based on spectral comparison with lactams 222 and 253. Rf = 0.28 (20:1 CHCl 3 /MeOH); IH NMR (CDC1 3 , 300 MHz, α indicates major isomer, β indicates minor isomer; ratio α/β = 1.7:1) δ 7.2-7.4 (m, 5Ha + 5Hb), 4.81 (dd, J = 4.3, 5.9 Hz, lHα), 4.69 (m, lHα + lHβ), 4.15-4.6 (m, 3Hα + 4Hβ), 4.27 (dd, J = 6.6, 13.5 Hz, lHβ), 4.12 (d, J = 13.5 Hz, lHα), 3.80 (m, lHα + lHβ), 3.4-3.65 (m, 2Hα + 3Hβ), 3.30 (m, lHα + lHβ), 3.10 (dd, J = 5.2, 13.5 Hz, lHα), 2.35-2.55 (m, 2Hα + lHβ), 1.9-2.2 (m, 2Hα + 3Hβ), 1.60 (m, lHα + lHβ), 1.51 (s, 3Hβ), 1.41 (s, 3Hα), 1.34 (s, 3Hβ), 1.32 (s, 3Hα); 13 C NMR (CDC1 3 , 75 MHz, α indicates major isomer, β indicates minor isomer) δ 167.7 (β), 167.6 (α), 137.3 (β), 173.2 (α), 128.2, 127.6, 127.5, 1 13.8 (β), 111.7 (α), 83.5 (β), 79.5 (α), 77.5 (α), 76.6 (β), 73.1 (OC), 73.0 (β), 70.0 (β), 68.6 (α), 68.4 (β), 65.8 (α) 64.9 (β), 50.4 (α), 48.9 (β), 38.7 (α), 36.6 (α), 35.9 (β), 35.7 (β), 32.4 (α), 29.2 (β), 27.5 (β), 26.4 (α), 25.3 (β), 24.6 ( ); IR (neat) 3350 (br m), 2935 (m), 2836 (m), 1626 (s) cm "1 ; MS (CI, NH 3 ) m/z (rel intensity) 362 [(M + H)+, 100]; HRMS (CI, NH 3 ) calcd for C 20 H 27 NO 5 H [(M + H)+] 362.1967; found 362.1983. (lS,2R,7S,8R,8aR)-7-[2-(Benzyloxy)ethyI]-8-hydroyx-l,2-0-isopropyIidenedioxy- indolizidine (330) and (lS,2R,7S,8S,8aS)-7-[2-(Benzy!oxy)ethyl]-8-hydroxy-l,2-0- isopropylidene-dioxyindolizidine (331). Reduction of the mixture of lactams 326 and 327 (1.7: 1, 235 mg, 0.65 mmol) was carried out with borane-methyl sulfide complex. Chromatography (100: 1 to 25: 1 CH 2 Cl 2 /Me0H gradient) provided 125 mg (55%) of the indolizidine 330 as a white crystalline solid followed by 70 mg (31%) of the indolizidine 331 as a pale yellow oil. Data for 330 (major): Rf = 0.35 (20: 1 CHCl^eOH); [α] 23 D = -42.3° (c 0.66, CHC1 3 ); mp 85 °C; IH NMR (CDC1 3 , 300 MHz) δ 7.2-7.4 (m, 5H), 4.73 (dd, J = 4.5, 6.2 Hz, IH, HI), 4.61 (dd, J = 4.3, 6.2 Hz, IH, H2), 4.52 (ABq, J = 12.2 Hz, Dn = 19.7 Hz, 2H), 3.89 (d, J = 2.5 Hz, IH, HOH), 3.60 (m, IH, H10), 3.52 (m, IH, H8), 3.49 (dt, J = 3.8, 9.4 Hz, IH, H10), 3.13 (d, J = 10.6 Hz, IH, H3eq), 2.99 (ddd, J = 2.5, 4.0, 10.8 Hz, IH, H5eq), 2.10 (dd, J = 4.3, 10.7 Hz, IH, H3ax), 1.90 (m, 2H, H5ax,9), 1.68 (dd, J = 4.5, 8.9 Hz, IH, H8a), 1.55-1.65 (m, 2H, H6,9), 1.52 (s, 3H), 1.35-55 (m, 2H, H6.7), 1.34 (s, 3H); 13 C NMR (CDC1 3 , 75 MHz) δ 137.6, 128.4, 127.9, 127.7, 111.0, 79.2, 78.5, 73.1, 73.0, 71.4, 69.1, 59.8, 51.6, 42.8, 34.2, 31.7, 25.9, 24.5; IR (neat) 3450 (br m), 2934 (s), 2856 (m), 2786 (m), 1370 ( ) cm-1; MS (CI, NH 3 ) m/z (rel intensity) 348 [(M + H)+, 88], 330 (42), 256 (31), 107 (100), 91 (88); HRMS (CI, NH 3 ) calcd for C 20 H 29 NO 4 H [(M + H)+] 348.2175; found 348.2168. Data for 331 (minor): Rf = 0.26 (20:1 CHCl 3 /MeOH); [α] 23 D = -3.6° (c 0.50, CHC1 3 ); IH NMR (CDC1 3 , 300 MHz) δ 7.2-7.4 (m, 5H), 4.69 (ddd, J = 5.1, 6.5, 7.2 Hz, IH, H2), 4.54 (s, 2H), 4.48 (dd, J = 5.7, 7.3 Hz, IH, HI), 3.59 (m, 2H, H10.8), 3.46 (m, IH, H10), 3.35 (dd, J = 6.3, 9.3 Hz, IH, H3eq), 3.24 (d, J = 5.3 Hz, IH, HOH), 2.65, (ddd, J = 2.5, 4.5, 11.4 Hz, IH, H5eq), 2.43 (dd, J = 5.1, 9.3 Hz, IH, H3ax), 2.33 (td, J = 2.9, 12.0 Hz, IH, H5ax), 2.24 (dd, J =5.6, 9.8 Hz, IH, H8a), 2.11 (m, 2H, H7.9), 1.76 (m, IH, H6), 1.59 (ddd, J = 2.6, 5.2, 13.8 Hz, IH, H6), 1.52 (s, 3H), 1.46 (m, IH, H9), 1.33 (s, 3H); 13 C NMR (CDC1 3 , 75 MHz) δ 137.8, 128.4, 127.7, 127.6, 114.1, 83.5, 77.6, 73.2, 72.7, 69.8, 68.7, 59.4, 46.2, 37.3, 30.0, 27.2, 26.9, 25.0; IR (neat) 3450 (br m), 2932 (s), 2859 (m), 2800 (m), 1372 (m) cm-1; MS (CI, CH 4 and NH 3 ) m/z (rel intensity) 348 [(M + H)+, 100], 330 (45), 256 (50), 91 (30); HRMS (CI, CH 4 and NH 3 ) calcd for C 20 H 29 NO 4 H [(M + H)+] 348.2175; found 348.2181. 333 (lS,2R,7S,8R,8aR)-7-[2-(Benzyloxy)ethyl]-l,2,8-trihydroxy-indoIizidine [(7S)-7-(2- Benzyloxyethyl)-swainsonine] (333). The acetonide of the indolizidine 330 (100 mg, 0.29 mmol) was hydrolyzed with 6 N HCl in THF. Recrystallization from EtOAc provided 77 mg (86 %) of 333 as a white solid. Rf = 0.18 (50:25: 1 EtOAc/EtOH/Aq. NH40H); [α] 23 D = -20.5° (c 0.78, CH 3 OH); mp 174°C; IH NMR (CD30D, 300 MHz) δ 7.2-7.4 ( , 5H), 4.52 (m, IH, H2), 4.50 (ABq, J = 11.7, Dn = 20.4 Hz, 2H), 4.36 (m, IH, HI), 3.66 (t,J = 10.0 Hz, IH, H8), 3.61 (t, J = 6.3 Hz, 2H, H10), 3.41 (m, 2H, H5 and H3), 3.31 (dd, J = 4.5, 11.9 Hz, IH, H3), 3.02 (dd, J = 1.8, 9.9 Hz, IH, H8a), 2.93 (td, J = 2.5, 12.5 Hz, IH, H5), 2.21 (m, IH, H9), 2.04 (m, IH, H6), 1.68 (m, IH, H7), 1.48 (m, 2H, H6 and H9); 13 C NMR (CD30D, 90 MHz) δ 139.8, 129.5, 129.1, 128.9, 74.1, 73.7, 69.9, 69.8, 69.2, 68.9, 60.2, 41.0, 32.6, 28.7; IR (neat) 3280 (br s), 2939 (m), 2864 (m), 1101 (s) cm-1; MS (CI, NH 3 ) m/z (rel intensity) 308 [(M + H)+, 100], 270 (25), 254 (24), 106 (21), 91 (29); HRMS (CI, NH 3 ) calcd for C 17 H 24 N0 4 H [(M + H)+] 308.1862; found 308.1850. REFERENCES 1. Mekki, B.; Singh, G. and Wightman, R. H. Reactions of 2,3-O-Isopropylidene Derivatives of Furanose Sugars with Organomagnesium and Organolithium Nucleophiles. Tetrahedron Lett. 1991, 32, 5143-5146. 2. Wolff, H. In Organic Reactions; Adams, R., Ed.; Wiley: New York, 1946: Vol. 3; pp 307-336. Example 1 1 Activity of Analogues Inhibition of Mannosidase II and lysosomal α-mannosidases by SW analogues. SW and analogues were serially diluted in 0.4 fold increments and 10μl added to 96 well Elisa plates followed by the addition of 10 μl of 200 mM sodium acetate pH 5.6 and 2.5 μl of 10 mM p-nitrophenyl, and 5 μl of either α-mannosidase II or lysosomal mannosidase. For lysosomal mannosidase, the 200mM sodium acetate buffer was adjusted to pH 5.0. The reaction was stopped by the addition of 50 μl of 0.5 M sodium carbonate and formation of p-nitrophenol was measured with a plate reader at 405 nm. Inhibition of L-PHA toxicity by SW analogues. MDAY-D2 tumor cells were inoculated into 96 well micro-test plates at 2 x 10 4 cells/well, and containing serial dilutions of SW analogues in MEM plus 10% FCS. The cells were cultured for 18-20 hr, followed by the addition of L-PHA at 25 μg/ml for an additional 24 hr. Cell proliferation was measured by adding 0.5 μCi/well of 3 H-thymidine for 3-4 hr, harvesting onto glass fibre disks using a Titertek harvester and the disks were counted in a liquid scintillation counter. The apparent IC 50 values for SW analogues are the drug concentrations showing 50% protection from L-PHA toxicity; that is 50% 3 H-thymidine incorporated compared with cells grown in the absence of L-PHA. The results of the biological activity studies for the analogues of the invention are shown in Table 1. While the present invention has been described with reference to what are presently considered to be the preferred examples, it is to be understood that the invention is not limited to the disclosed examples. To the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. All publications, patents and patent applications are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety. TABLE 1 Comparison of IC50 Data Enzyme: Man II Compound ID Mean IC50 (μM) ratio M/L* Structure swainsonine 0.084357 0.8 (6S)-6-Ethylswainsonine (275) 2.166667 0.2 (6S)-6-(2-Benzyloxyethyl)swainsonine (276) 5.116667 0.33 (7S)-7-(2-Benzyloxyethyl)swainsonine (305) 5.53 0.24 (7R)-7-(2-Benzyloxyethyl)swainsonine (304) 28.466 0.02 (7S)-7-Butyl-8,8a-Diepiswainsonine (334) 2000 (6R)-6-Ethylswainsonine (277) 44.54 0.47 (7S)-7-Butylswainsonine (332) 2000 (7R)-7-Butyl-8,8a-diepiswainsonine (308) 2000 HO H I -* * & ratio of activity mannosidase II lysosomal mannosidase

Claims: WE CLAIM: 1. A compound of the formula I wherein (a) R', R 3 and R 5 are the same or different and represent hydrogen, alkyl, or aryl; (b) R 2 , R 4 and R 6 represent hydroxyl or alkoxy; and one of Y and Y' represents hydroxyl, alkyl, cycloalkyl, alkenyl, alkynyl, unsaturated monocyclic hydrocarbon, aryl, alkoxy, or aryloxy, and the other of Y and Y' represents hydrogen, and Z and Z' represent hydrogen; or, one of Z and Z' represents alkyl, cycloalkyl, alkenyl, alkynyl, unsaturated monocyclic hydrocarbon, aryl, alkoxy, or aryloxy and the other of Z and Z' represents hydrogen, and Y and Y' represent hydrogen, and isomers and pharmaceutically acceptable salts thereof. 2. A compound as claimed in claim 1 wherein R', R 3 , and R 5 are the same and represent hydrogen, and R 2 , R 4 , and R 6 are the same and represent hydroxyl. 3. A compound of the formula I as claimed in claim 1 wherein R', R 3 , and R 5 represent hydrogen, and R 2 , R 4 , and R 6 represent hydroxyl, and Z and Z' represent hydrogen, one of Y and Y' represents methyl, ethyl, phenyl, benzyl, methoxy, or 2-benzyloxyethyl, and the other of Y and Y' represents hydrogen. 4. A compound of the formula I as claimed in claim 1 wherein R', R 3 , and R 5 represent hydrogen, and R 2 , R 4 , and R 6 represent hydroxyl, and Y, and Y' represent hydrogen, one of Z and Z' represents methyl, ethyl, phenyl, benzyl, methoxy, or 2-benzyloxyethyl, and the other of Z and Z' represents hydrogen. 5. A compound of the formula I which is (lS,2R,6S,8R,8aR)-6-Ethyl-l,2,8 trihydroxyindolizidine [(6S)- 6-Ethyl-swainsonine] ; ( 1 S,2R,6R,8R,8aR)-6-Ethyl- 1 ,2,8-trihydroxyindolizidine [(6S)-6-Ethyl- swainsonine]; (lS,2R,6R,8R,8aR)-6-[2-(Benzyloxy)ethyl]-l,2,8-trihydroxyindolizidine [(6R)-6-(2- Benzyloxyethyl)-swainsonine];(lS,2R,7R,8R,8aR)-7-Butyl-l,2,8-trihydroxy-indolizidine [(7R)-7-Butyl- swainsonine]; (lS,2R,7R,8S,8aS)-7-Butyl-l,2,8-trihydroxy-indolizidine [(7R)-7-Butyl-8,8a- diepiswainsonine]; (lS,2R,7R,8R,8aR)-7-[2-(Benzyloxy) ethyl]- 1,2,8-trihydroxyindolizidine [(7R)-7-(2- Benzyloxyethyl)swainsonine]; (lS,2R,7S,8S,8aS)-7-Butyl-l,2,8-trihydroxyindolizidine [(7S)-7-Butyl- swainsonine]; (lS,2R,7S,8S,8aS)-7-Butyl-l,2,8-trihydroxyindolizidine [(7S)-7-Butyl-8,8a- diepiswainsonine]; (lS,2R,7S,8R,8aR)-7-[2-(Benzyloxy)ethyl]-l,2,8-trihydroxyindolizidine [(7S)-7-(2- Benzyloxyethyl)swainsonine] ; or ( 1 S,2R,7S,8R,8aR)-7-[2-(Benzyloxy)ethyl]- 1 ,2,8- trihydroxyindolizidine [(7S)-7-(2-Benzyloxyethyl)swainsonine]. 6. A pharmaceutical formulation comprising a compound of the formula I as claimed in any one of claims 1 to 5 as an active agent, and a pharmaceutically acceptable carrier, excipient or diluent. 7. A method for stimulating the immune system, treating proliferative disorders, or microbial infections in a patient comprising administering an effective amount of a compound of the formula I as claimed in any one of claims 1 to 5. 8. Use of a compound as claimed in any one of claims 1 to 5 in the manufacture of a pharmaceutical for use in stimulating the immune system, treating proliferative disorders, or microbial infections in a patient.

Inventors: DENNIS JAMES, HEMBRE ERIK, PEARSON WILLIAM, SHAH RAJAN, TROPPER FRANCOIS D, DENNIS, JAMES, HEMBRE, ERIK, PEARSON, WILLIAM, SHAH, RAJAN, TROPPER, FRANCOIS, D.
Applicants: DENNIS JAMES, GLYCODESIGN INC, HEMBRE ERIK, PEARSON WILLIAM, SHAH RAJAN, TROPPER FRANCOIS D, DENNIS, JAMES, GLYCODESIGN INC., HEMBRE, ERIK, PEARSON, WILLIAM, SHAH, RAJAN, TROPPER, FRANCOIS, D.
Application year: 1997
Main classification: C07D471
IPC codes: A61K31, A61P31, A61P35, A61P37, C07D471