BICYCLIC CHIRAL COMPOUNDS

Abstract: A compound of general formula I(a) and/or I(b) and/or I(c), in which R<1> represents a methyl group or a group of the general formula -CH2.SO2.R<2> or -CH2.SO2.NR<2>R<3>, in which each of R<2> and R<3> independently represents an alkyl, cycloalkyl or optionally substituted phenyl or phenalkyl group; each of R<4>, R<5> and R<6> independently represents a hydrogen atom or a methyl group; X represents a group of formula C(CH3)2 or, when both of R<5> and R<6> represent methyl groups, also represents a group of formula CH2; Q represents an oxygen or sulphur atom; and Y represents a hydrogen atom, an alkali metal atom or a group of the general formula -COA in which A represents a halogen atom or an alkyl or alkoxy group optionally substituted by a phenyl, cycloalkyl, alkoxy or alkylcarbonyl group. The compounds are bicyclic optically active compounds and are useful in the synthesis of optical isomers and separation of optical isomers from mixtures.

Description: BICYCLIC CHIRAL COMPOUNDS The present invention relates to novel bicyclic chiral compounds. Much research is currently devoted to methods of producing optically active compounds. Some compounds can be synthesised directly in a form containing an excess of a desired isomer, using optically active starting materials or an optically active catalyst. Other materials are more conveniently prepared in isomeric form by separation of the desired isomer from a mixture. A number of chiral reagents useful in such separations are known. We have now found a family of novel bicyclic optically active compounds useful in the separation of particular isomers from mixtures. Accordingly, the present invention provides a compound of the general formula 1(a), 1(b) and/or 1(c): Ka) Kb) in which R* represents a methyl group or a group of the general formula -CH2.SO2. 2 or -CH2.Sθ2.NR 2 R 3 , in which each of R 2 and R 3 independently represents an alkyl, cycloalkyl or optionally substituted phenyl or phenalkyl group; each of R*, R^ and R° independently represents a hydrogen atom or a methyl group; X represents a group of formula 0(0.3)2 or > whe both of R 5 and R^ represent methyl groups, may also represent a group of formula CH2; Q represents an oxygen or sulphur atom; and Y represents a hydrogen atom, an alkali metal atom or a group of the general formula -COA in which A represents a halogen atom or an alkyl or alkoxy group optionally substituted by a phenyl, cycloalkyl, alkoxy or alkylcarbonyl group. Throughout this specification, the structurally isomeric compounds 1(a), 1(b) and 1(c) will be referred to jointly as the compounds I. The compounds I exist in a number of optical and geometric isomeric forms, and the formulae 1(a), 1(b) and 1(c) should be understood to embrace all such forms. An optionally substituted phenyl or phenalkyl group R^ and/or R 3 may carry one or more of the inert substituents commonly carried by a phenyl group. Such substituents may for example by selected from halogen atoms and alkyl, alkoxy, haloalkyl, haloalkoxy, nitro, alkylcarbonyl and alkoxycarbonyl groups. In such a group, any alkyl moiety preferably has from 1 to 4, especially 1 or 2, carbon atoms. A substituted phenyl group preferably has up to 3, especially 1 or 2, substituents. The alkyl moiety in a phenalkyl group preferably has from 1 to 4, especially 1 or 2, carbon atoms. An alkyl group R 2 and/or R 3 preferably has up to 20, more preferably up to 10, especially 4 to 8, carbon atoms. A cycloalkyl group R 2 and/or R 3 is preferably a cyclopentyl or, especially, cyclohexyl, group. The number of carbon atoms in an alkyl or alkoxy group A is not crucial. Preferably such a group has up to 30 carbon atoms. Where a higher alkyl or alkoxy group is preferred, such a group may for example have from 15 to 30 carbon atoms. Where a lower alkyl or alkoxy group is preferred, such a group preferably has up to 6, especially up to 4, carbon atoms. A cycloalkyl substituent on an alkyl or alkoxy group A is preferably a cyclopentyl or cyclohexyl group and an alkoxy or alkylcarbonyl substituent preferably has up to 6, especially up to 4, carbon atoms in the alkyl moiety. Preferably Q represents an oxygen atom. Compounds (I) may be prepared by ring closure of a suitable precursor. The position of ring closure determines the proportion of each isomer 1(a), 1(b) and/or 1(c). Accordingly, the invention further provides a process for the preparation of a compound of the general formula 1(a), 1(b) and/or 1(c), which comprises inducing ring closure in a compound of the general formula II in which R , R^, R^, R 6 and X have the meanings given for. the general formulae 1(a), 1(b) and 1(c), and Z represents an -N3 group or a group of tr.e general formula -NH.O.SO2.R , in which R' represents an optionally substituted phenyl group; and if desired, converting the resulting compound in which Y represents a hydrogen atom into the corresponding compound in which Y represents an alkali metal or a group of formula -CO.A; and if desired, converting a resulting compound in which Q represents an oxygen atom into the corresponding compound in which Q represents a sulphur atom. The compounds of the general formula II are novel, and form a further aspect of the present invention. In general, cyclisation of a compound of the general formula II leads to a mixture of two or three of the possible structural isomers 1(a), 1(b) and/or 1(c). These isomers may be separated by known methods, for example chromatography. For preparation of a compound of the general formula 1(a), R^ in the starting material II must represent a hydrogen atom. For preparation of a compound of the general fomula 1(b), R in the starting material II must represent a methyl group. The O.CO.Z group in a compound of the general formula II may be exo or endo to the bicycloheptane ring, and cyclisation leads to the corresponding compound I in which the oxazolidinone ring is exo or endo to the bicycloheptane ring. A compound 1(c) can only be prepared from a compound of formula II in which the O.CO.Z group is endo to the bicycloheptane ring. A compound of the general formula II in which Z is an -N3 group may be cyclised by heating, for example to a temperature in the range of from 70 to 300 β C. The heating may be carried out in the presence or absence of a solvent. The spray pyrolysis apparatus described in Accts. Chem. Res.. 1987, 2fJ, 18 or the flash vacuum pyrolysis apparatus described in EP-A-259103 may preferably be used. If a solvent is used, this may for example be a hydrocarbon or a chlorohydrocarbon, preferably tetrachloroethane. Ultra-violet photolysis or microwaves may also be used, again preferably in the presence of a hydrocarbon or chlorohydrocarbon solvent. Where Z in a compound of the general formula II represents a group of the general formula -NH.O.Sθ2-R^, ^ may represent any suitable optionally substituted phenyl group, for example one of those listed for R^ above. Especially suitable groups R' are phenyl and p_-nitrophenyl groups. Such a compound of the general formula II may be cyclised by treatment with a base in a homogeneous or two phase system. Examples of the homogeneous system are the use of a ine bases such as triethylamine, or sodium bicarbonate in a chlorinated solvent such as dichloromethane or hydrocarbon/substituted hydrocarbon solvent such as nitromethane. Reaction in an organic-aqueous two-phase system is performed using a similar selection of organic solvents with, referably, aqueous sodium bicarbonate as the basic solution. In addition a quaternary ammonium or phosphonium salt as phase-transfer catalyst, preferably benzyltriethylammonium chloride, may be employed. The temperature may be for example in the range 20-100*C, preferably 20-30 # C. A compound I in which Y represents a hydrogen atom may be converted into the corresponding compound in which Y represents an alkali metal atom by reaction with a suitable strong base, and into the corresponding compound in which Y represents a group COA by reaction with a compound of formula HalCOA, in which Hal represents a halogen atom. Such conversions may be carried out by known methods. A compound I in which Q represents an oxygen atom may be converted into the corresponding compound in which Q represents a sulphur atom by methods analogous to known methods, for example by reaction with phosphorus pentasulphide or with Lawesson's reagent. A compound of the general formula II may be prepared by reaction of a compound of the general formula III: in which R 1 , R^, R 5 , R 6 and X have the meanings given for the general formula II, with an alkali or alkaline earth metal azide, preferably sodium azide, to produce a compound of the general formula II in which Z represents an -N3 group, or with hydroxyammonium chloride followed by a compound of the general formula CI.SO2.R 7 , or with a compound of formula NH2 0 • so 2- R7 > in wh ich R 7 has the meaning given for the general formula II, to produce a compound of the general formula II in which Z represents an -NH.O.SO2.R 7 group. A compound of the general formula III may be prepared by reaction of a compound of the general formula IV: in which Ri, R*, R^, R6 an d x have the meanings given for the general formula II, with phosgene. The reaction is suitably carried out in the presence of a suitable solvent, for example an ether such as diethyl ether, tetrahydrofuran or 1,4-dioxan and in the presence or absence of a base such as pyridine or triethylamine, at a temperature in the range of from -10*C to 20*C, preferably -5*C to lO'C. The reaction is preferably carried out under an inert atmosphere. The compounds of the formula IV are either naturally occuring or can be obtained from naturally occuring compounds by known methods. They include endo-(lS)-l,7,7-trimethylbicyclo-[2.2.l]-heptan-2-ol ((-)-borneol); endo-(lR)-l,7,7-trimethylbicyclo[2.2.1]heptan-2-ol ((+)-borneol), preparable by reduction of (+)-camphor; exo-(lS)-l,7,7- trimethylbicyclo[2.2.1]heptan-2-ol, preparable by S-selectride reduction of (-)-camphor; exo-(lR)-l,7,7- triraethylbicyclo[2.2.1]heptan-2-ol, preparable by LS-selectride reduction of (+)-camphor; the reduction products of (-)-fenchone and (+)-fenchone; and the products preparable by methylation of (-)-camphor or (+)-camphor at the 3-positions followed by reduction to the alcohol. LS-Selectride is the compound LiB CH.CH3.CH(CH CH3)2)3H. Compounds in which R* represents a group of the general formula -CH2.SO2.R 2 or -CH2.SO2.NR 2 R 3 may be prepared from the corresponding compounds in which R represents a -CH2.SO2.Cl group by known methods, for example as described in Tet. Letters 1984, 25, 5885. The compounds I may be used as resolving agents for other optically-active compounds. For example, compounds in which Y represents -COHal where Hal is a halogen atom may be used to separate enantiomers of amines, amino-acids, alcohols or thiols whilst compounds in which Y represents an alkali metal atom may be used to separate enantiomers of acid halides or amino-acid halides. In addition, compounds I in which Y represents a group - COA where A is an optionally substituted alkyl group, may be used to react with non-optically active compounds, for example aldehydes, ketones, keto-acids and epoxides, generating optical centres stereoselectively. Accordingly, the present invention also provides a process for separating enantiomers of a compound capable of reacting with a compound I, which comprises contacting a mixture of said enantiomers with a compound I, and separating the resulting components of the mixture. The invention further provides a process for generating an optically active carbon atom from an optically inactive carbon atom, which comprises reacting a compound of the general formula I in which A is an optionally substituted alkyl group, with an alkylating agent such as an aldehyde, ketone, keto-acid, alkyl halide or epoxide. Compounds I in which Y represents -COA where A is an unsaturated group of formula RCH-CH- (R-H,Me,Ph or any substituted or unsaturated alkyl group) may be used for reaction with chiral dienes, original reagents and 1,3-dipoles enabling, in some cases, the simultaneous generation of more than one optically active centre in a si.gle step operation. Compounds of formula I in which Q represents a sulihur atom are chiral derivatising agents of improved UV sensitivity for chromatographic monitoring. Compounds of formula I in which Y represents CONHOH could also be used as a basis for ligands for complexing to metals as optically active catalysts or reagents. The following Examples illustrate the invention. Examples 1, 2 and 9 describe the preparation of compounds of the formula (III). Examples 3 to 5 and 10 describe the preparation of compounds of the formula II. Examples 6 to 8, 11, 29 to 31 and 33 describe the preparation of compounds I. Examples 28 to 32 describe the use of compounds I. Example 1 Preparation of endo-(lS)-!,7,7-trimethylbicyclor2.2.1lheptan-2-chloroformate A solution of endo-(lS)-(-)-borneol (9g, 5.8xlO _2 M) and dry pyridine (4.61g, 5.8xl0 _ ra) in anhydrous diethyl ether (200 ml) was added dropwise to a rapidly stirred solution of phosgene (20Z in toluene, 86 ml, 1.74xl0~^m) under argon at 0°C. The reaction mixture was stirred at room temperature for 4 hours and filtered. The precipitate was washed well with anhydrous diethyl ether. The ether fractions were combined and evaporated in vacuo to yield endo-(lS)-l,7,7-trimethylbicyclo[2,2,l]heptan-2-chloroformate as a pale yellow oil (12.lg, 971); b.p. 0 . 7 85*C (Kugelrhor); &X] 21 . 5 D - -36.7*; [o] 2 l.° D - -36.8°, c - 5.1 (EtOH); M + 216.0917 C 11 H 17 C10 2 requires 216.0917; *H nmr (200 MHz, CDC1 3 ) 50.8-0.9 (3s, 9H, 3xCH 3 ), 1.0 - 2.5 (m, 7H), 5.0 (ddd, IH, CH0)," max (thin film) 1780 cm -1 . Example 2 Preparation of exo-(lS)-!.7.7-trimethylbicyclor2.2.11 heptan-2-chloroformate The method of Example 1 was repeated using exo-(lS)-l,7,7-trimethylbicyclo[2.2.1]heρtan-2-ol to produce the desired product in 86X yield. b.p.Q-7 70 β C; [c_] 21 . 5 D - -54.5 β , c = 4.9 (EtOH); X H nmr (200 MH Z , CDC1 3 )S0.84 (s, 3H, CH 3 ), 0.92 (m, 3H), 0.99 (s, 3H, CH3), 1.08 (s, 3H, CH3), 1.7 (m, 3H), 3.93 (dd, IH, J * 4.66 H3, CH) . l) max thin film 1765 cm- . Example 3 Preparation of endo-(lS)-!,7,7-trimethylbicyclof2.2.ll-heptan-2-azidoformate endo-(lS)-l,7,7-Trimethylbicyclo[2.2.1]heptan-2-chloroformate (lOg, 4.6xl0 _2 m), the product of Example 1, in CH2CI2 (50 ml) was added in one to a rapidly stirred solution of sodium azide (6.0g, 9.2xl0~ 2 m) and tetrabutylammonium bromide (0.2g) in water (50 ml). The reaction mixture was stirred for 4 hours, separated and the aqueous fraction ws extracted with CH2CI2 (x2). CH2 I2 fractions were combined, washed with H2O (xl), dried (MgSθ, and evaporated in vacuo to yield a slightly yellow oil endo-(lS)-l,7,7-trimethylbicyclo[2.2.1]-heptan-2-azidoformate (10.lg, 98%); b.p. 0 . 15 85*C (Kugelrhor); |<X] 22 . 5 D = -42.3°, c - 4.9 (EtOH); M + 223.13207 C 11 H 17 N 3 0 2 requires 223.1321; X H nmr (200 MH Z , CDCI3) S 0.86 (s, 3H, CH3), 0.87 (s, 3H, CH3), 0.89 (s, 3H, CH3), 1.08 (dd, IH, J - 13.96 H z , 3.42 Hz, CH), 1.28 (m, 2H, CH 2 ), 1.78 (m, 3H), 2.39 (m, IH, CH), 4.89 (m, IH, CHO). 13 C nmr (50.3 MH Z , CDCI3)5157.42 (C=0), 84.58 (CHO), 48.83 (quart. C), 47.77 (quart. C), 44.53 (CH), 36.10 (CH 2 ), 27.65 (CH 2 ), 26.56 (CH 2 ), 19.39 (CH3), 18.53 (CH3) 13.14 (CH3); 13 C assignments are based on ^/ 2 and T 3 / DEPT measurements; max 2150, 2115 (-N3), 1720 (C«0) cm -1 . Example 4 Preparation of exo-(1S)-1.7.7-trimethylbicyclor2.2.1lheptan-2-azidoformate The method of Example 3 was repeated using exo-(1S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-chloroformate to produce the desired product in 97Z yield. b.p. 0 . 5 105 β C; [o<] 2 . 0 D - -19.5", c - 4.9 (EtOH); M + 223.1321 C 11 H 17 N 3°2 requires 223.1321, L H nmr (200 MH 2 , CDCI3) S 0.82 (s, 3H, CH3), 0.87 (s, 3H, CH3), 0.93 (s, 3H, CH3), 1.08 (m, 2H, CH 2 ) 1.56 (m, 2H, CH 2 ) 1.77 (m, 3H), 4.65 (m, IH, CHO); 13 C nmr (50.3 MHz CDCI3) S 156.53 (C-0), 85.48 (CHO), 48.79 (quart. C), 46.63 (quart. C), 44.67 (CH), 38.11 (CH 2 ), 33.2 (CH 2 ), 26.60 (CH 2 ), 19.67 (CH 3 ), 19.43 (CH 3 ), 10.90 (CH 3 ). > max (thin film) 2170, 2140 (N 3 ), 1730 (C-0) cm" 1 . Example 5 Preparation of endo-(lS)-!,7,7.-trimethylbicyclof2.2.1lheptan-2- p-nitrobenzenesulphonoxy carbamate The product of Example 1 (7g, 0.032 m) in diethyl ether (10 ml) was added dropwise to a cooled (O'C), stirred mixture of finely ground hydroxya monium chloride (2.5g, 0.035 m) and potassium carbonate (4.4g, 0.032 m) in diethyl ether containing water (0.5 ml). The mixture was stirred at room temperature for 12 h, the precipitate was filtered off and the solvent removed in vacuo to give endo-lS-(-)bornyl-N-hydroxy-carbamate. p-Nitrobenzenesulphonyl chloride (4.65g, 0.021 m) was added gradually to an ice-cooled, stirred solution of the N-hydroxycarbamate (0.021 m) in dry diethyl ether (150 ml). Triethylamine (0.018 m) in dry diethyl ether (25 ml) was added dropwise, ensuring that the reaction mixture remained acidic at all times. The mixture was stirred at room temperature for 48 hours, the precipitate was filtered off and the filtrate evaporated to give the required product, endo-lS-(-)-bornyl p_-nitrobenze_e-sulphonoxycarbaraate as a yellow solid (7.63 g, 90%). This was recrystallised from chloroform/hexane to give fine, cream needles, m.p. 138-139'C (Found: C, 51.5; H, 5.63; N, 7.04. C 17 H 2 2θ7 2S requires C, 51.3; H, 5.6; N, 7.0%); >) max (mull) 3240, 3200, 1750, 1705, 1535 and 1195 cm" 1 ; X H nmr (200 MHz; CDC1 3 )$9.6 (IH, br s), 8.27 (4H, m), 4.75 (IH, m), 2.4-0.6 (16H, cm); i3 C (50 MHz; CDCl 3 )8l55.85, 157.17, 139.15, 130.71, 123.98, 83.75, 48.79, 47.74, 44.47, 35.94, 27.65, 26.64, 19.37, 18.47 and 12.97; m/z 398 (M + ), 383, 340, 292, 264, 217, 203, 196, 188, 154, 136, 121, 107, 97, 79. Example 6 The product of Example 3 (20g, 8.96xl0~ 2 m), was passed through a spray pyrolysis apparatus at 300*C and a vacuum of 0.1-0.05mm Hg. Product was collected in a vessel cooled with dry ice in an amount of 16.08g (922). This was purified by column chrometography using Fluka Kieselgel 60 using initially n-hexane (200ml), petroleum ether 40-60: ethyl acetate, 9:1 (500ml), 4:1 (500ml), 3:1 (1500ml), to yield pioducts (a), (b) and (c) as follows, (a., Endo-,9S,4R)-l-oxa-3-aza-8.10.10-trimethyltricyclo.3.2.1.0 , 9 ] - decjii-2-one Yield 57% Spray Pyrolysis; m.p. 163 - 163.5°C, [<*] 21 . 5 D - -73.4°, c - 5.1 (EtOH); Found C, 67.6; H, 9.0; N, 7.2. CnH 17 N02 requires C, 67.7; H, 8.8; N, 7.2%, l E nmr (200 MHz, CDCI3) S 0.90 (s, 3H, CH3), 0.94 (s, 6H, 2 x CH3), 1.30 (m, 2H, CH 2 ), 1.65 (m, 2H, CH 2 ), 1.87 (m, IH, CH), 4.16 (dd, IH, J = 9.82 Hz, 4.68 Hz, CH) 4.60 (dd, IH, J - 9.94 Hz, 1.68 Hz, CH) , 5.56 (bs, IH, NH); 13 C nmr (50.3 MHz, CDC1 3 ) S 160.50 (C=0), 85.71 (CH), 54.66 (CH), 49.04 (quart. C) , 48.44 (CH), 29.51 (quart. C) 26.34 (CH 2 ), 19.97 (CH 3 ), 19.71 (CH 2 ), 17.82 (CH 3 ), 14.00 (CH3); V max 3300 (bs, NH), 1755 (s, C=0), 1715 (s, NH) cm -1 . (b) Endo-(10S)-l-oxa-3-aza-l1.1l-dimethyltricvclo.4.3.1.0 5 . 10 .- undecan-2-one Yield 17%; m.p. 170 - 171'C; [ot] 23 .° D -+72.l β , c - 5.1 (EtOH); Found: C, 67.5; H, 8.8; N, 7.1. C11H17NO2 requires C, 67.7; H, 8.8; N, 7.2%; X H nmr (200 MHz, CDCI3) S 0.94 (s, 3H, CH 3 ), 0.95 (s, 3H, CH 3 ), 1.37 (m, 3H), 1.8 (m, 2H, CH 2 ), 2.95 (dd, IH, J = 10.7 Hz, J = 3.9 Hz, CH b N), 3.3 (d, IH, J = 10.7 Hz, CH a N), 4.51 (ddd, IH, J = 10.1 Hz, 4.4 Hz, 2.0 Hz, CHO), 6.25 (bs, IH, NH); 13 C nmr (50.3 MHz, CDCI3) S 155.92 (C-0), 80.24 (CH), 46.16 (quart. C), 45.86 (CH), 44.48 (quart. C), 43.50 (CH 2 ), 32.75 (CH 2 ), 27.36 (CH 2 ), 24.50 (CH 2 ), 19.72 (CH3), 18.42 (CH3); ^ max (KBr) 3345 (bs, NH), 1713 (s, C-0), 1668 (s, NH). (c) Endo-(4R,8S)-l-oxa-3-aza-9.10.10-trimethyltricyclol.3.1.1.1]— decan-2-one Yield 25%; m.p. 170*C; Found: C, 67.4; H, 9.0; N, 7.1. C n H 17 N0 2 requires C, 67.7; H, 8:8; N, 7.2%, X H nmr (200 MHz, CDCI3) 53.45 (m, IH, CHN), 4.5 (m, IH, CHO), 7.1 (bs, NH); 13 C nmr (50.3 MHz, CDCI3) 5152.31 (C-0), 82.69 (CH), 54.24 (CH), 48.58 (quart. C) , 46.10 (quart. C), 41.28 (CH), 39.22 (CH 2 ), 36.63 (CH 2 ), 19.24 (CH3), 18.64 (CH 3 ), 11.07 (CH3). In addition to the procedure described above, the product of Example 3 was pyrolysed used a flash vacuum pyrolysis apparatus. Product (a) was obtained in 46% yield, product (b) in 23% yield, and pi duct (c) in 23% yield. Exa _ple 7 The product of Example 4 was pyrolysed by the procedures described in Example 6 to yield products (a) and (b) as follows, (a) Exo-(9S.4S)-l-oxa-3-aza-8, 10.10-trimethyltricycloF3.2.1.0 4 , 9 1- decan-2-one Yield 58% (S.P.), 55% (F.V.P.); m.p. 153.5 - 154.5 β C; [«*] 22 . 0 D = 35.1°, c = 5 (EtOH); Found: C, 67.5; H, 8.9; N, 7.2. C 11 H 17 N0 2 requires C, 67.7; H, 8.8; N, 7.2%; H nmr (200 MHz, CDC1 3 ) S °- 86 ( s > 3H, CH 3 ), 0.95 (m, IH, CH), 1.00 (s, 3H, CH3), 1.06 (s, 3H, CH3), 1.59 (m, 3H), 1.83 (d, IH, J - 4.47 Hz, CH), 3.73 (d, IH, J = 8.1 Hz, CH), 4.34 (d, IH, J - 8.1 Hz, CH), 6.63 (bs, IH, NH); 13 C nmr (50.3 MHz, CDCI3) 5 160.59 (C-0), 88.25 (CH), 68.48 (CH), 48.47 (CH), 48.03 (quart. C), 46.17 (quart. C), 31.58 (CH 2 ), 24.60 (CH 2 ), 23.12 (CH3), 19.25 (CH 3 ), 10.66 (CH 3 ); ? max (KBr) 3300 (bs, NH), 1765 (s, C-0), 1716 (s, NH) cm -1 , (thin film) 3200 (bs, NH), 1745 (s, C-0), 1690 (s, NH) cm -1 . (b) Exo-(IPS)-l-oxa-3-aza-l1,11-dimethyltricyclor4.2.1.0 5 , 10 1undecan- 2-one Yield 43% (S.P.), 27% (F.V.P) m.p. 177 - 178*C; [ ] 23 .° D -+8.1', [βC] 22 .° D - +7.1*. c - 5.1 (EtOH); Found: C, 67.3; H, 8.85 N, 7.2. C 11 H 17 N0 2 requires C, 67.6; H, 8.8; N, 7.1%; 1 H (200 MHz, CDC1 3 )S0.89 (s, 3H, CH 3 ), 1.09 (s, 3H, CH3), 1.10 (m, 2H, CH 2 ), 1.75 (m, 4H), 2.10 (m, IH, CH), 3.27 (m, 2H, NCH 2 ), 4.26 (dd, IH, J - 14.29 Hz, (7.15 Hz, CHO), 6.27 (bs, IH, NH); l3 C nmr (50.3 MHz, CDCI3) S 154.95 (C-0), 83.13 (CH), 46.34 (quart. C), 44.98 (CH), 43.71 (quart. C) 39.78 (CH 2 ), 38.08 (CH 2 ), 30.59 (CH 2 ), 26.63 (CH ), 19.92 (2 x CH3); Y> max (thin film) 3240 (bs, NH), 1690 (s, C-0) cm -1 . Example 8 Preparation of Oxazolidinones Utilizing Lwowski Type Reagent Benzyltriethylammonium chloride (O.lg, 4.39 mm.) was added to a stirred mixture of the product of Example 5 (lg) (3.5 g., 8.75 mm) in aqueous sodium hydrogen carbonate solution (1M, 50 ml), and dichloromethane (180 ml.). The reaction mixture was stirred vigorously overnight at room temperature, following which dichloromethane (100 ml.) was added and the mixture washed with water (3 x 50 ml). The organic phase was dried (MgSθ4) the solvent removed and the reaction mixture subjected to column chromatography (Siθ2, gradient elution 10/90 v/v - 100/0 v/v ethyl acetate/n-hexane). Three fractions were collected in the following order:- (a) endo-(lS)-!,7,7-trimethylbicyclof2.2.1 ]heptan-2-carbamate (0.234g, 14%); m.p. 124 - 126 β C; [*] 22 D = -34.4°, c = 4.96 (EtOH); M + 197.1425 C il H 19 N0 2 requires 197.1421; : H nmr (200 MHz, CDCI3) ξ> 0.83 (s, 3H, CH 3 ), 0.84 (s, 3H, CH 3 ), 0.88 (s, 3H, CH 3 ), 0.97 (dd, IH, J - 13.7 Hz, 3.4 Hz), 1.19 (m, 2H), 1.61 (m, 2H), 1.84 (m, IH), 2.24 (m, IH), 4.74 (ddd, IH, J - 9.9 Hz, 3.3 Hz, 2Hz, CHO), 5.11 (bs, 2H, NH 2 ); 13c ( 50 - 3 MHz. CDC1 3 ) 157.5 (C-0), 80.4 (CHO), 48.6 (quart. C), 47.7 (quart. C), 44.7 (CH), 36.5 (CH 2 ),, 27.8 (CH 2 ), 26.7 (CH 2 ), 19.5 (CH 3 ), 18.6 (CH 3 ), 13.3 (CH 3 ); \> max (KBr) 3480, 3340 (m, w, NH 2 ), 1700, 1605 (s, ra, C0NH 2 ) cm -1 . (b) Endo-(9S.4R)-l-oxa-3-aza-8.10.10-trimethyltricyclof3.2.1.0. , 9 1 -decan-2-one (0.74g, 43%). (c) Endo-(10S)-l-Oxa-3-aza-ll.ll-dimethyltricvclof4.2.1.0. 5 . 10 1 -undecan-2-one (0.62g, 36%). Example 9 Preparation of exo-(lR)-l-N.N-dicyclohexylsulphonamidomethyl- 7.7-dimethylbicyclof2.2.1lheptan-2-chloroformate This compound was prepared from exo-(lR)-l-N,N- dicyclohexylsulphonamidomethyl-7,7-dimethylbicyclo[2.2.1]heptan-2-ol (lg, 2.52 x 10~ 3 m) using the method shown in Example 1 in 97% yield (1.12g, 2.44 x 10~ 3 m) as a white crystalline solid; m.p. 129 - 131*C; Found: C, 60.1; H 8.4; N, 3.14. C 23 H38N0 SC1 requires C, 60.1;H, 8.3; N, 3.0%; [o_] 21 κ - -39.2', c - 4.5 (CH 2 C1 2 ); X H nmr (200 MHz, CDCI3) S 0.9 (s, 3H, CH3), 1.0 (s, 3H, CH3), 1.1 - 1.4 (m, 8H), 1.5 - 1.8 (ra, 16H), 1.9 (m, 3H), 2.6 (d, IH, J - 14.4 Hz, CHS0 2 ), 3.2 (d, IH, J = 14.4 Hz, CHS0 2 ), 3.3 (tt, 2H, CHN), 5.15 (dd, IH, J - 7.11 Hz, 4.2 Hz, CHO); max (KBr) 1780 (s, C-0) cm -1 . Example 10 Preparation of exo-(lR)-l-N,N-dicyclohexylsulphonamidomethyl- 7,7-dimethylbicyclof2.2.1lheptan-2-azidoformate The method of Example 3 was repeated using the product of Example 9 to produce this compound in 78% yield (0.32 g), 6.8 x 10~^m) as a white crystalline material; m.p. 143 - 144 β C; [e ] 23 D = -14.1°, c = 1.2 (CH2C1 2 ); Found: C, 59.2; H, 8.4; N, 12.1. C23H38N4O4S requires C, 59.2; H, 8.2; N, 12.0%; m/z 466; H nmr (200 MHz, CDCI3) S 0.9 (s, 3H, CH3), 0.94 (s, 3H, CH 3 ), 1.0 - 1.4 (m, 8H), 1.5 - 2.1 (m, 18H), 2.6 (d, IH, J - 13.4 Hz CHS0 2 ), 3.1 (d, IH, J - 13.4 Hz, CHS0 2 ), 3.2 (tt, 2H, CHN), 5.0 (dd, IH, J - 7.0 Hz, CHO). Example 11 Thermolysis of exo-(lR)-l-N,N-dicyclohexylsulphonamidomethyl- 7,7-dimethylbicyclor2.2.11heptan-2-azidoformate A solution of the above compound (0.826 g, 1.77 x 10 ~3 m) in 1,1,2,2-tetrachloroethane (TCE, 50 ml.) was refluxed (147 β C) under argon for 2 hours. The solvent was removed in vacuo and the crude reaction mixture subjected to column column chromatography (Siθ2, 50 g, gradient elution 95:5 40-60 pet. ether: ether to 100% ether). Two fractions were collected containing higher Rf and lower Rf as viscous oils in a ratio of 2.64: 1 in yields of 55.5% and 21% respectively. The higher Rf material was exo-(9R,4S)-l-oxa-3-aza-8-N,N-dicyclohexyl-sulphonamidomethyl-10, 10- dimethyltricyclo[3.2.1.0 , 9 ]decan-2-one; M + 438.2549 C 2 3H3 8 N 2 θ4S requires 438.2552; M 24 D - - 38.9', c-0.9 (EtOH); X H nmr (200 MHz, CDC1 3 ) £ 0.9 (s, 3H, CH3), 1.04 (s, 3H, CH3), 0.8 - 2.0 (m, 27H) 2.71 (d, IH, J - 13.4 Hz, CHS0 2 ); 3.20 (d, IH, J - 13.4 Hz), CHS0 2 ), 3.25 (tt, 2H), 3.77 (d, IH, J - 8.1 Hz, CHN), 4.98 (d, IH, J - 8.1 Hz, CHO), 6.7 (s, IH, NH). Example 12 This example describes the conversion of a compound of formula 1(a) in which Y is a hydrogen atom into the corresponding compound in which Y is a C2H5CO- group, and reaction of the resulting compound with racemic benzaldehyde. In the reaction with benzaldehyde, a new optically active centre is generated. (a) Preparation of endo-(9S.4R)-N-proρionyl-l-oxa-3-aza-8,10,10- trimethyltricyclor3.2.1.0 4 ,"]decan-2-one A solution of the product of example 6(a) (2g, 1.02 x 10 ~ ^m) in .mhydrous toluene (sodium) (100 ml.) was added to a stirred suspension of oil free sodium hydride (0.27 g, 1.12 x 10 ~ 2m) in toluene (30ml.) under argon. The reaction mixture was heated under reflux for 60 minutes, cooled to room temperature, and treated dropwise with propionyl chloride (l.Og, 1.08 x 10 _2 m) in toluene (3 ml). The mixture was stirred for a further 60 minutes, poured into saturated NaHC03 solution and the two fractions were separated. The organic fraction was washed with water, dried (MgSθ4 and evaporated to yield a colourless oil (2.62 g). The oil was purified by high vacuum distillation b.p.Q.25 165*C (Kugelrohr); 2.43 g., 95%; [θt] 26 D . -150.6°, c = 5 (EtOH); M + 251.1524, C 1 4H 2 ι 0 3 requires 251.1521; λ E nmr (200 MHz, CDC1 3 ) 5 0.90 (s, 3H, CH3), 0.91 (s, 3H, CH3), 0.93 (s, 3H, CH3), 1.09 (t, 3H, CH3, J - 7.34 Hz), 1.1 - 1.7 (m, 4H), 2.24 (t, IH, CH, J - 4.0 Hz), 2.90, dq, 2H, CH 2 , J = 7.73 Hz, 7.29 Hz), 4.45 - 4.6 (m, 2H); 13 C nmr (50.3 MHz, CDCI3) $ 174.0 (C-0), 154.2 (C-0), 82.4 (CHO), 57.5 (CH), 49.2 (quart. C), 48.3 (quart. C), 47.6 (CH), 28.8 (CH 2 ), 26.1 (CH 2 ) 19.7 (CH 2 ), 17.8 (CH 3 ), 13.6 (CH3), 8.1 (CH 3 ); max (thin film) 1780 (s, C=0), 1700 (s, C-0) cm -i . (b) Procedure for Generation of Lithium Enolates and Subsequent Aldol Reaction A solution of lithium diisopropylamide (2.18 mm, 1.1 eq.) was prepared by addition of butyllithium (1.6 M in hexane, 1 eq., 1.36 mm) dropwise to a solution of anhydrous diisopropylamine (0.221 g., 0.31 ml, 2.18 mm, 1.1 eq.) in dry THF (30 ml.) at O'C. The reaction mixture was left at this temperature for 0.5 hours before cooling to -78*C. The N-propionylimide of part (a) (1.98 mm, 0.498 g, 1 eq.) was then added as a solution in THF (5 ml) and the reaction mixture left for a further 0.5 hours at -78*C. Neat redistilled benzaldehyde was added rapidly (1.98 mm, 0.206 ml, 0.21 g, 1 eq.) and the reaction quenched after 30 seconds with saturated ammonium chloride solution (5 ml). Water (50 ml) was added and the reaction products extracted into ether. The organic layer was dried ( gS04) and taken to dryness to give a white crystalline mixture of the aldol adducts (0.69 g, 97%, 1.92 mm). 360 MHz nmr spectroscopy showed there to be all four possible diastereomeric aldol adducts present in a ratio of approximately 55.4 : 28.7 : 10.3 : 5.7. (r) Procedure for Generation of Dibutylboron Enolate and Subsequent Aldol Reaction To a solution of imide (300 mg, 1.2 mm) in CH2CI2 (5 ml) at 0°C was added di-n-butylboron triflate (1M, in CH2CI2 . 1.31 ml, 1.31 mm) followed by diisopropylethylamine (0.25 mol, 1.43 mm). The mixture was stirred for 30 minutes then cooled to -78°C and a solution of the aldehyde (1.31 mm) in THF (1 ml) was added dropwise. The solution was stirred at -78"C for 30 minutes and then at RT for 1.5 h. The mixture was quenched with pH7 phosphate buffer (50 ml) and the organic phase separated. The aqueous layer was extracted with CH2CI2 and the combined extracts were evaporated in vacuo. The resulting oil was then treated with 30% w/v H2O2 (2 ml) in methanol (2 ml) at 0*C for 1 hr. The mixture was then thoroughly extracted with ether and the extracts were dried (Na2Sθ4) and evaporated. The products were isolated following purification by flash chromatography. (i) Reaction with isobutyraldehyde gave a single diastereoisomer (86%) as a colourless solid melting point 161-2*C (ethyl acetate-petrol (Found: C, 66.8; H, 9.32; N, 4.44, C18H29NO4 requires C, 66.84; H, 9.04; N, 4.33); \) max (Nujol) 1770, 1660 cm -1 ; m/z (ci) 324 (M + + 1, 20%), 306(100%), 252(95%), 196(80%), : H nmr 84.64-4 (2H, m), 4.02 (IH, gd, J6, 2.5Hz), 3.52 (IH, dd, J8, 2.5Hz), 2.87 (IH, br, OH), 2.30 (IH, t, J4Hz), 1.75-1.58 (3H, m), 1.40 (IH, m) 1.23 (3H, d, J7Hz), 1.15 (IH, m), 1.02 (3H, J7Hz), 0.99 (3H, s), 0.98 (3H, s), 0.97 (3H, s), 0.90 (3H, d, J7Hz). (ii) Reaction with benzaldehyde gave a single diastereoisomer (52%) as a colourless crystals melting point 136-7'C (ethyl acetate-petrol (Found: C, 66.62; H, 9.01; N, 4.32. C21H2 NO4 requires C, 66.84; H, 9.04; N, 4.33); ^ max 1770, 1658 cm -1 ; X H nmr §7.42-7.21 (5H, m), 5.12 (IH, d, J3.5Hz), 4.58-4.45 (2H, m), 4.14 (IH, gd, J7,3.5Hz), 3.00 (IH, br, OH), 2.30 (IH, t, J4Hz), 1.73-1.55 (2H, m), 1.44-1.05 (2H, m), 1.17 (3H, d, J7Hz), 0.98 (6H, brs) 0.95 (3H, s). Example 13 Use of the N-carbamoyl chloride of endo-(9S.4R)-l-oxa-3_ aza-8,10,10- trimethyltricyclof3.2.1.0 4 , 1decan-2-one for the chromatographic resolution of R- and S-1-Phenylethylamine. This Example describes the reaction of an equivalent of a compound 1(a) with an amine, to produce two diastereomeric products which can be separated by chromatography. A 20% solution of phosgene in toluene (83.7 ml, 16.75 g, 1.69 x 10~^m, 15 eq.) under argon was stirred overnight with calcium hydride (0.2 g) to remove free hydrogen chloride. The product of example 6(a) (2.2 g, 1.12 x 10~lm) in dry THF (50 ml) under argon was treated dropwise with 1.6 M solution of n-butyl lithium (7.75 ml, 0.79 g, 1.24 x 10~ 2 m, 1.1 eq.) and stirred for 30 minutes at room temperature. The phosgene solution was cooled to 0*C in an ice bath and treated dropwise via a metal canula (id 2.2 mm gc tubing) using slight positive argon pressure with the lithium salt over 15 minutes. The reaction mixture was stirred at room temperature for 2 hours then filtered. The precipitate was washed with THF and the organic fraction containing product and excess phosgene evaporated in vacuo to yield a white solid (moisture sensitive) (2.65 g, 91%). FAB-MS (M+l) + 258.08968 C 12 H 17 C1N0 3 requires 258.08969; X H nmr (60 MHz, CDC1 3 ) S 0.89 (S, 3H, CH3), 0.91 (S, 6H, 2 x CH3), 1.2-1.8 (m, 4H), 2.4 (m, IH), 4.7 (m,2H, CHO, CHN); 13 C nmr (50.3 MHz, CDCI3) S 150.57 (C-0), 144.66 (C-0), 81.84 (CHO), 60.15 (CHN), 49.39 (quart.c), 48.22 ' (quart.c), 48.03 (CH), 26.02 (CH 2 ) 19.55 (CH 2 , CH3), 17.85 (CH3), 13.51 (CH3); _> max (nujol mull), 1833 (S, C-0, C0.C1), 1745 (S, C-0) cm -1 ; )> max (KBr) 1830 (S, C-0, C0.C1), 1740 (S, C-0) cm -1 . The carbamoyl chloride (63 mg, 0.244 mm) was dissolved in toluene (sodium-dried, 5 ml.) with triethylamine (1.5 eq, 0.367 mm), (±)-l-phenylethylaraine (1.01 eq, 0.247 mm) was then added neat to the reaction mixture and the reaction refluxed for 1 hour. After cooling, ether (30 ml) was added and the reaction mixture extracted with hydrochloric acid (1M, 10 ml). The organic layer was separated, dried (MgSθ4) and the solvents removed to yield an oily mixture (95%, 79 mg) of diastereoisomeric ureas. A "Hichrom" column (25 cm. x 0.46 cm., 5 micron Spherisorb Si0 2 , flow rate = 2 ml./min., detector = 260 nm) was used for the H.P.L.C determination of o.-values. The diastereomers were eluted with 1 : 4 v/v ether : n-hexane. An O.-valve of 2.01 was obtained. The reaction was repeated on a larger scale (1.24 mm) and diastereoisomeric ureas were separated by column chromatography (80g, "Flash" Si0 2 , gradient elution 1 : 9 v/v to 1 : 1 v/v ether : 40 - 60 pet. ether) yielding 98% (0.407 g). Higher Rf diastereomer X H nmr (200 MH Z , CDCI3) S 0.89 (s, 3H, CH3), 0.95 (s, 3H, CH3), 0.96 (s, 3H, CH3), 1.50 (d, 3H, J - 7.0 Hz), 1.75 - 2.0 (m, 4H), 2.27 (M, IH), 4.51 (m, 2H), 4.97 (m, IH), 7.21 - 7.32 (m, 5H), 8.27 (d, IH, J - 7.5 Hz, NH). Lower Rf diastereomer X H nmr (200 MHz CDCI3) 8 0.89 (s, 3H, CH 3 ), 0.95 (s, 3H, CH3), 0.96 (s, 3H, CH3), 1.48 (d, 3H, J = 6.9 Hz), 1.75 - 2.0 (m, 4H), 2.24 (m, IH), 4.58 (m, 2H), 5.02 (m, IH), 7.3 (m, 5H), 8.27 (d, IH, J - 7.6 Hz). Example 14 Use of the N-Carbamoyl Chloride of endo-(9S,4R)-l-oxa-3-aza-8, 10,10- trimethyltricyclor3.2.1.0 4 , ldecan-2-one for the Kinetic Resolution of R- and S-1-Phenylethylamine. This Example differs from Example 13 in that an excess of amine is used. The compound 1(a) reacts selectively with one of the two isomers of the amine. The carbamoyl chloride (2.5 g, 9.70 x 10~ m) in dichloromethane (30 ml) was added dropwise over 4 hours to a stirred ice-cold solution of (±)-l-phenylethylamine (2.35 g, 1.94 x 10" 2 m) and triethylamine (0.98 g, 9.70 x 10~ 3 M) in dichloromethane (10 ml) under argon. The reaction mixture was washed with 2M HCL (10 ml), dried ( gSθ ) and evaporated in vacuo to yield a white crystalline mass (3.28 g, 98%). The 2 diastereomers were separated by column chromatography to yield higher Rf diastereomer (0.75 g, 23%) and lower Rf diastereomer (2.4 g, 73%). Example 15 The Use of N-carbamoyl chloride of endo-(9S,4R)-l-oxa-aza-8,10,10- trimethyltricyclof3.2.1,0 4 , ldecan-2-one For The Chromatographic resolution of R- and S-N-Methyl-2-phenylethylamine A stirred solution of this carbamoyl chloride (0.252 g, 9.7 x 10 -4 M) in ether (40 ml) under argon was treated with triethylamine (0.14 g, 1.46 x 10 ~ m) followed by (±)-N-methyl-2-phenylethylamine (0.132 g, 9.78 x 10 ~4 m). The resultant mixture was kept at 20° for 60 minutes then poured into water (30 ml). The 2 fractions were separated and the ether fraction was dried ( gS04 and evaporated to yield a mixture of the diastereomers. An H.P.L.C. o- -value of 1.2 was measured for the pair of diastereomers (1 : 1 v/v ether : n-hexane as eluant). X H nmr (200 MHz, CDC1 3 ) &0.90 (s, 3H), 0.91 (s, 3H) , 0.93 (s, 3H), 1.57 (s, 3H), 1.75 - 2.0 (m, 4H), 2.09 (m, IH), 2.71 (d, 3H, J = 7.0 Hz), 4.53 (dd, IH, J - 13.6 Hz, 1.2 Hz), 4.75 (dd, IH, J - 13.4 Hz, 9.6 Hz), 4.81 (dd, IH, J - 13.6 Hz, 9.8 Hz), 5.50 (q, IH, J = 6.9 Hz), 5.55 (q, IH, J - 7.1 Hz), 7.3 (M, 5H). Example 16 The Use of Sodium Salt of endo-(9S.4R)-l-oxa-3-aza-8.10,10- trimethyltricyclor3.2.1.0 4 . ldecan-2-one For The Chromatographic Separation of R- and S-2-Bromopropionyl Bromide The oxazolidinone (0.868 g, 4.45 mm) was dissolved in toluene (sodium dried, 20 ml). Sodium hydride was added (ether washed, 1.1 eq, 0.117 g, 4.875 mm) and the reaction magnetically stirred under argon for 1 hour at 20*C. 2-Bromopropionyl bromide (0.5 ml, 1.03 g, 4.77 mm) was added neat to the suspension of the sodium salt by means of a syringe and the reaction mixture stirred for a further hour at ambient temperature. After this time water (30 ml) was added and the reaction mixture extracted into ether. The ether solution was dried (MgS04) and taken to dryness to yield a white crystalline mixture of the two disastereioraers. These could easily be separated by column chromatography (80g, Siθ2 5 : 95 v/v to 50 : 50 v/v ether/n-hexane) to yield the higher Rf diastereomer in 36% yield (0.524 g) and the lower Rf diastereomer in 52% yield (0.763 g). An H.P.L.C. O -value of 2.1 was measured using an eluant mixture of 20 : 80 v/v ether:n-hexane. Higher Rf diastereomer - Found: C, 50.8; H, 6.12; N, 4.2. 14 H 20 NO 3 Br requires C, 50.9; H, 6.1; N, 4.2%; m.p. 82 - 84"C; m/z 3'i, 329, 287, 285, 272, 270, 250, 206; M + 329.0618 C 1 4H 2 o0 3 N 79 Br requires 329.0627; H nmr (200 MHz, CDCI3) δ 0.96 (s, 3H), 0.97 (s, 3H), 0.99 (s, 3H), 1.0 - 1.75 (m, 4H), 1.83 (d, 3H, J - 6.8 Hz), 2.33 (m, IH), 4.58 (m, 2H, CHO, CHN), 5.78 (q, IH, J - 6.8 Hz). Lower Rf diastereomer - m/z 331, 329, 287, 285, 272, 270, 250, 206; M + 329.0617 C 14 H 2 oθ3N 7 Br requires 329.0627; 1 H nmr (200 MHz, CDCI3) g θ . 92 ( s , 3H) , 0 . 94 (s , 3H) , 0. 95 ( s , 3H) , 1 .0 - 1 . 75 (m, 4H) , 1 . 76 (d , 3H, J - 6 .6 Hz) , 2.28 (m, IH) , 4. 55 (m, 2H, CHO , CHN) , 5 . 73 (q, IH, J - 6.6 Hz) . Example 17 The Use of Sodium Salt of endo-(9S,4R)-l-oxa-3-aza-8, 10,10- trimethyltricyclo[3.2.1.0 4 , ldecan-2-one For the Chromatographic resolution of R- and S-2-Phenylpropionyl Chloride The oxazolidinone (0.653 g, 3.35 x 10~ 3 m) was dissolved in toluene (20 ml, sodium dried) and sodium hydride added (ether washed), (1.1 eq, 0.088 g, 3.68 x 10~ 3 m). The reaction was stirred under argon for 1 hour at ambient temperature and treated with neat (±)-2-phenylpropionyl chloride (0.56 g, 3.35 x 10~ m) added via a syringe and the reaction stirred for a further hour. Water was added (30 ml) and the reaction mixture extracted with ether. The ether layer was dried ( gSU4) and taken to dryness to give a crude yield of a mixture of diasteroisomeric amides (1.10 g, 97%). A small portion of this mixture was analysed by H.P.L.C. and an o^-value of 2.08 measured using a 20 : 80 v/v mixture of ether and n-hexane as eluant. The remaining crude reaction was subjected to column chromotography and diastereoisomers easily separated (70 g, SiO∑, 5 : 9 to 1 : 1, ether: n-hexane). Higher Rf diastereomer X H nmr (200 MHz, CDC1 3 ) S θ.91 (s, 3H), 0.95 (s, 3H), 0.97 (s, 3H), 1.0 - 1.48 (m, 2H), 1.49 (d, 3H, J = 7.0 Hz), 1.57 - 1.73 (m, 2H), 2.34 (t, IH, J - 4.02 Hz), 4.45 (m, 2H, CHO, CHN), 5.18 (q, IH, J - 7.0 Hz), 7.3 (m, 5H). Lower Rf diastereomer X H nmr (200 MHz, CDCI3) S 0.88 (s, 3H), 0.91 (s, 3H), 0.92 (s, 3H), 1.0 - 1.5 (m, 4H), 1.47 (d, 3H, J - 7.0 Hz), 2.18 (t, IH, J - 3.90 Hz), 4.46 (dd, IH, J - 13.6 Hz, 1.2 Hz), 4.59 (dd, IH, J - 13.6 Hz, 9.8 Hz), 5.16 (q, IH, J - 7.0 Hz), 7.35 (m, 5H); 13 C nmr (50.3 MHz, CDCI3) S 174.6, 153.7, 140.2, 128.4, 128.1, 127.0, 82.3, 57.6, 49.3, 48.4, 47.6, 42.8, 42.6, 26.1, 19.9, 19.8, 19.7, 13.7; ? max(KBr) 1770, 1700 (s, C-0) cm" 1 . Example 18 Kinetic Resolution of 2-Chloropropionyl Chloride with sodium salt of endo-(9R.4R)-l-oxa-3-aza-8.10.10-trimethyltricyclof3.2.1.0 . 9 1 decan-2-one This oxazolidinone (0.73 g, 3.74 x 10 -3 m) in dichloromethane (10 ml) was added dropwise to a stirred suspension of oil free sodium hydride (0.089 g, 3.74 x 10~ 3 m) in ether (3 ml) under argon at 0*C. The reaction mixture was stirred at 20* for 3 hours, cooled to 0* and treated dropwise with 2-chloropropionyl chloride (0.95 g, 7.48 x 10 ~ 3 m) in dichloromethane (20 ml) over 6 hours. When addition was complete the reaction was stirred at 20 'C for 1 hour and evaporated to dryness, taken up in dichloromethane (20 ml) and washed with water (5 ml), saturated NaHC03 solution (10 ml), dried (M S04) and evaporated in vacuo to yield a white crystalline solid (0.81 g, 84%) of the diastereoisomeric amides. A sample was subjected to H.P.L.C. and yielded an ©<-value of 2.1 The products were separated easily by column chromatography (Siθ2, 9 : 1 to 1 : 1 v/v n-hexane : ether) to yield higher Rf diastereomer (0.5 g) and lower Rf diastereomer (0.27 g). Example 19 The Use of the N-Carbamoyl chloride of exo-(9S,4R)-l-oxa-3-aza- 8.10.10-trimethyltricvclof3.2.1.0 , 9 1decan-2-one for the Kinetic Resolution of R- and S-1-Phenylethylamine The carbamoyl chloride (1.81 g., 7.02 x 10" 3 m, 1 eq) in anhydrous dichloromethane (50 ml) was added dropwise to an ice-cold solution of (±)-l-phenylethylamine (1.70g, 1.40 x 10~ 2 m, 2 eq) and triethylamine (0.70 g, 7.02 x 10~ m, 1 eq) in dichloromethane (10 ml) under argon over 7 hours. The reaction mixture was poured into 2M HCl (5 ml). The two fractions were separated, dried (MgS04) and evaporated to yield two white solid (2.3 g, 96%). H.P.L.C. analysis of the crude reaction mixture showed that there had been selective diastereoisomeric urea formation in the ratio of 4 : 1 and an ©_-value of 1.3. Example 20 The conversion of endo-(9S.4R)-l-oxa-3-aza-8.10.10-trimethyltricyclo [3.2.1.0 , 9 ]decan-2-one into compounds where Y=C0A in which A is RCH-CH- (a) Preparation of acrylate (R-H) To an ice-cooled solution of oxazolidinone of example 6(a) (0.5 g, 2.56 x 10" 3 m) in freshly distilled THF (c_a 40 ml) under argon, MeMgBr (3.0 M in diethylether, 0.9 ml, 2.7 x 10 "3 m, 1.05 equiv.) was added. The resulting solution was then stirred at 0*C for ten minutes before the temperature was lowered to -78 β C. Freshly distilled 2-propenoyl chloride (0.3 g, 3.3 x 10" 3 m, 1.3 equiv.) was then added and the resulting solution stirred at -78*C for ten minutes and then at 0*C for 75 minutes. The reaction was then quenched with aqueous ammonium chloride and extracted into ether (3 x c_a 75 ml). The combined organic extracts were washed with saturated NaHC03, brine and dried over gSθ4- Filtration and evaporation of solvent in vacuo yielded a solid which was purified by column chromatography (60 g Siθ2 7:1 n-hexane/EtOAc) yielding a white solid (0.48 g, 75%); melting point - 47-50'C; [X] 21 . 5 D - -156.9*, c-2.58 CH2CI2); M+-249.13648; C 1 4H 19 N0 3 requires 249.136475; X H nmr (200 MHz, CDCI3) $ 7.55 (dd, J-17 and 10.48Hz, IH), 6.50 (dd, J-17 and 1.92Hz, IH), 5.85 (dd, J-10.45 and 1.86Hz, IH), 4.66-4.49 (cm, 2H, CHO and CHN), 2.31 (t, J-4.2HZ, IH), 1.70-1.09 (m, 4H, CH 2 ), 0.97-0.95 (m, 9H); 13 C nmr (50.3 MHz, CDCI3) & 164.96, 154.04, 131.39, 127.19, 82.63, 57.82, 49.33, 48.44, 47.68, 26.18, 19.76, 19.66, 17.92, 13.67; ^ max (Nujol) 2930, 1770, 1690, 1620, 1460, 1415, 1380 cm -1 , (b) Preparation of crotonate (R-Me) To a freshly prepared, cooled (0*C) solution of MeMgBr (0.73 g, 6.15 x 10" 3 m, 1.2 equiv.) in freshly distilled diethylether (ca 30 ml), a solution of oxazolidinone (1 g, 5.13 x 10- m) in freshly iistilled THF (ca 30 ml) was added. The resulting solution was allowed to stir at 0*C for twenty minutes before being cooled to -78"C. Freshly distilled crotonoyl chloride (0.65 g, 6.22 x 10 _3 m, 1.2 equiv.) was then added and the resulting solution stirred at -78 β C for twenty minutes and then at 0 β C for c_a one hour. The reaction mixture was then allowed to stir at ambient temperature overnight after which time thin layer chromatography revealed the presence of a trace of starting material. The reaction mixture was quenched with ammonium chloride solution and extracted into ether (3 x ca SO ml). The combined ether extracts were washed with saturated sodium bicarbonate solution and brine and dried over MgSθ . Removal of the solvent in vacuo yielded a pale yellow solid which was purified by flash chromatography (50 g Siθ2 7:1 n-hexane/EtOAc) to yield a white solid (1.15 g, 85%); melting point 117-121 β C, [ e*] 21 . 5 D —173.9°, c-4.94 (CH 2 C1 2 ); M+-263.15213 C 15 H 21 N0 3 requires 263.152125; *H nmr (200 MHz, CDC1 3 ) 57.27 (dq, J-15.25 and 1.50Hz, IH, CH-CHCO), 7.05 (dq, IH, J-15.26 and 6.56Hz, MeCH-CH-), 4.56 (ddd, J-9.8, 4.3 and 1.22Hz, CHN), 4.45 (ddd, J-9.78, 2,2 and 0.6Hz, IH, CHO), 2.24 (t, IH, J-4.2Hz, CH), 1.88 (dd, J-6.69 and 1.44Hz, 3H, CH3), 1.61-1.08 (cm, 4H, 2xCH 2 ), 0.91-0.90 (2xS, 9H, CH3); 13 C nmr (90.56 MHz, CDCI3) 8164.95, 154.05, 146.17, 121.65, 82.34, 57.76, 49.25, 48.30, 47.78, 26.17, 19.71, 19.59, 18.19, 17.85, 13.60; max (Nujol) 2920, 1763, 1682, 1635, 1375, 1208, 1050 cm -1 , (c) Preparation of cinnamate (R-Ph) To a freshly prepared solution of MeMgBr (0.38 g, 3.20 x 10~ 3 m, 1 equiv.), in dry diethylether (ca 10 ml) at 0*C under argon, was added a solution of oxazolidinone (0.624 g, 3.2 x 10~ 3 m) in dry THF (ca 40 ml). The resulting solution was stirred at 0*C for ten minutes before being cooled to -78"C. A solution of cinnamoyl chloride (0.64 g, 3.84 x 10" 3 m, 1.2 equiv.) in dry THF (£a 5 ml) was then added and the resulting solution stirred at -78*C for twenty minutes before being warmed to ambient temperature and stirred overnight. The reaction was quenched with saturated NH4CI solution and the mixture concentrated in vacuo, diluted with H 2 0 (c_a 20 ml) and extracted into CH2CI2 (3 x ca 60 ml). The combined extracts were washed with saturated NaHCθ3 and brine and dried over MgSU4. Filtration and evaporation of the solvent yielded a solid which was purified by flash chromatography (60 g Siθ2, 7:1 n-hexane/EtOAc) to yield a white solid (0.84 g, 81%); melting point 169.5-170.5 β C (4:1 n-hexane/di-isopropylether), [o_ ] 23 . 5 D —133.0, c-4.22 (CH 2 C1 2 ); M+-325.16778 C20H23NO3 requires 325.167775; X H nmr (200 MHz, CDCI3) & 8.00 (d, IH, 15.73Hz, CH-CHCO), 7.81 (d, IH, J=15.74Hz, PhCH=CH-), 7.63-7.58 (cm, 2H, Ph), 7.39-7.34 (cm, 3H, Ph), 4.64 (ddd, IH, J-ll.l, 4.50 and 1.33Hz, CHN), 4.53 (dd, J-ll.l and 1.42Hz, IH, CHO), 2.35 (t, IH, J-8.41Hz, CH), 1.67-1.09 (cm, 4H, 2 x CH 2 ), 0.98-0.97 (2xS, 9H, CH 3 ); 13 C nmr (90.56 MHz, CDC1 3 ) S 165.16, 154.15, 145.80, 134.46, 130.33, 128.63, 128.37, 116.90, 82.43, 57.94, 49.29, 48.35, 47.82, 26.20, 19.73 19.66, 17.88, 13.62; i> max (Nujol) 2920, 1760, (C-0), 1680 (C-0), 1615 (C-C), 1378, 1368, 1210, 1048 cm -1 . Example 21 Reaction of endo-(9S.4R)-N-acryloyl-l-oxa-3-aza-8.10,10- trimethyltricyclor3:2:l:0^, ldecan-2-one with cyclopentadiene at -78*C (a) Using TiC^OPrl ? as catalyst To a solution of acrylate (0.162 g, 6.51 x 10~^m) in dry CH2CI2 (ca 2 ml) at -78*C under Ar was added TiCl (0.52 g, 2.74 x 10 _3 m, 4 equiv.) followed by Ti(0Prl)4 (0.74 g, 2.60 x 10" 3 m, 4 equiv.). Freshly cracked cyclopentadiene (0.43 g, 7.17 x 10~ m, 11 equiv.) was then added and the resulting solution stirred at -78*C for 21.5 hours before thin layer chromatography revealed that no starting material remained. The reaction mixture was poured onto crushed ice and extracted into CH 2 C1 2 (3 x ca 20 ml). The combined organic layers were washed with NaHC03 solution and brine and dried over MgS04. Filtration and evaporation of the solvent in vacuo yielded an oily solid which was purified by flash chromatography (50 g Siθ2, gradient elution n-hexane -> 1:1 n-hexane/ether) yielding a white solid (0.17 g, 83%) which contained a mixture of two endo isomers in a ratio 2:1, which were separated by careful column chromatography (70 g "TLC" silica, eluting with 40:1 n-hexane/ether. Minor (higher Rf) isomer; melting point 143-145.5 β C (n-hexane/diisopropylether), [tX ] 23 D =-25.1°, c=1.95 (CH 2 C1 12 ); M+-315.18343 C 19 H25N0 3 requires 315.183425; *H nmr (360 MHz, CDCI3) $6-20 (dd, IH, J=5.64 and 3.08Hz, =CH), 5.85 (dd, IH, J-5.64 and 2.85Hz, =CH), 4.49-4.48 (cm, 2H, CHO and CHN), 3.28 (GS, IH, CH), 2.91 (GS, IH, CH), 2.27-2.15 (cm, IH, CH), 1.97 (ddd, IH, J-12.77, 9.09 and 3.74Hz, CH 2 ), 1.68-1.06 (cm, 7H), 0.96 (S, 3H, CH3), 0.94 (S, 3H), 0.92 (S, 3H, CH 3 ); 13 C nmr (50.3 MHZ, CDC1 3 ) S 174.51, 153.93, 137.65, 131.50, 82.26, 58.07, 49.93, 49.23, 48.18, 47.76, 46.12, 43.09, 42.68, 29.42, 26.16, 19.55, 19.30, 17.83, 13.65; tf max (Nujol) 2924, 1770 (C-0), 1755 (C-0), 1695 (C-C), 1280, 1220, 1040 cm -1 . Major (lower Rf) isomer, melting point 155-157.5 β C, [oi ] 22 D —287.5*, c-3.08 (CH 2 C1 2 ); Found C, 72.3; H, 8.0; N, 4.4 C19H25NO3 requires C,72.5; H, 8.05; N, 4.72. M+-315.18343 C 19 H 2 5N0 3 requires 315.183425; X H nmr (200 MHz, CDCI3) _> 6.20 (dd, J-5.6 and 3.0Hz, 1H-CH), 5.77 (dd, J-5.6 and 2.8Hz, 1H-CH), 4.51 (ddd, J-9.9, 4.2 and 1.2Hz, IH), 4.45 (dd, J-9.3 and 1.3Hz, IH), 4.03 (ddd, J-9.0, 4.4 and 3.4Hz, IH), 3.36 (GS, IH), 2.90 (GS, IH), 2.19 (t, J-4.0Hz, IH), 1.86 (ddd, J-12.6, 9,0 and 4.7Hz, IH), 1.70-1.08 (m, 7H), 0.95 (S, 3H, CH3), 0.93 (S, 3H, CH 3 ), 0.90 (S, 3H, CH3); 13 C nmr (50.3 MHz, CHCI3) S 174.31, 153.89, 137.88, 130.95, 82.17, 57.62, 50.00, 49.18, 48.18, 47.53, 46.26, 42.79, 42.63, 28.80, 26.14, 19.60, 19.35, 17.73, 13.55; >) max (Nujol) 2920, 1790, 1775, 1640, 1460, 1380 cm -1 . (b) Using Bt«. A1C1 as catalyst To a solution of acrylate (0.102 g, 410 x 10~*m) in dry CH2CI2 (ca 2 ml) under Ar at -78°C was added freshly cracked cyclopentadiene (0.27 g, 4.1 x 10~ 3 m). To this rapidly stirred solution Et 2 AlCl (1.8 M in toluene, 0.3 ml, 5.40 x 10- 4 m. 1.4 equiv.) was added. After c_a three minutes, the reaction was quenched with HCl (2 m, c_a 5 ml) and stirred for five minutes. The organic layer was separated off and the aqueous layer extracted further with CH 2 C1 2 (3 x £ 10 ml). The combined organic layers were washed successively with saturated NaHC0 , brine and dried over MgSθ4. Filtration and evaporation of the solvent in vacuo and subsequent purification by column chromatography yielded a white solid (0.124 g, 98%) which contained the same two endo isomers but in a ratio of 4:1. Example 22 Reaction of endo-(9S.4R)-N-acryloyl-l-oxa-3-aza-8.10.10 trimethyltricyclo f3:2: 1:0 4 , ldecan-2-one with isoprene at -78"C (a) Using TiCl (O r catalyst Using the same protocol as for example 21(a), the reaction was conducted for 45.5 hours before quenching. Work-up provided a colourless oil (0.08 g, 802) which crystallised on standing. ^H NMR (360MHz) using a europium chiral shift reagent revealed that two isomers were present in a ratio 2:1. (b) Using Et^AlCl catalyst Adopting the same procedure as for example 21(b), work-up yielded a white solid (0.240 g, 94%) which contained the same two isomers in a ratio 5:1. Example 23 Reaction of endo-(9S.4R)-N-crotonoyl-l-oxa-3-aza-8.10,10 trimethyltricyclof3:2:l:0 , ldecan-2-one with cyclopentadiene at -78'C (a) Using TiCl ? (0Pr i ) ? as catalyst To a solution of TiCl4 (0.29, 1.53 x 10" 3 m, 4 equiv.) and Ti(0Pr i ) 4 (0.43 g 1.51 x 10 _3 m, 4 equiv.) in dry CH 2 C1 2 (ca 2 ml) at -78'C under Ar, was added a solution of crotonate (0.1 g, 3.8 x 10~ 4 m) in dry CH2C1 2 (ca 3 ml). Freshly cracked cyclopentadiene (0.25 g, 3.79 x 10~ m) was added and the resulting solution stirred at -78*C for 20 hours. The reaction was quenched by pouring onto crushed ice and extracted into CH 2 Cl2 (3 x ca 20 ml). The combined organic extracts were washed successively with saturated aHCθ3 and brine, dried over gS04, filtered and the solvent removed in vacuo to yield a cloudy oil which was purified by flash chromatography (50 g Siθ2, gradient elution n-hexane -> 1:1 n-hexane/ether) yielding a white solid (0.115 g, 92%) which was submitted for study by 360 MHz *H NMR. This revealed the presence of four isomers in the ratio 83:56:18:6. Major isomers were not characterised, due to the difficultly in separation of these compounds. ('J) Using Et ? AlCl as catalyst To a solution of crotonate (0.1 g, 3.8 x 10~ 4 m) in dry CH2CI2 (ca 2 ml) at -78'C under argon, was added Et2AlCl (1.8 M in toluene, 0.3 ml, 5.39 x 10~ 4 m, 1.4 equiv.). To the resulting bright yellow complex was added rapidly via connector, pre-cooled, freshly cracked cyclopentadiene (1 g, 0.015, 40 equiv.). After c_a five minutes the 27 colour had faded and the reaction mixture was diluted with CH2CI2 (ca 50 ml) and quenched with dilute HCl (2M a_ 10 ml). The organic layer was collected and the aqueous layer extracted further with ether (3 x ca 20 ml). The combined extracts were washed 5 successively with saturated aHC03, brine and dried over MgSθ4. Filtration and evaporation of the solvent in vacuo yielded a white solid (0.12 g, 96%) which contained the same four isomers in the ratio 36:8:2:8. Example 24 10 The reaction of endo(9S.4R)-N-cinnamoyl-l-oxa-3-aza-8,10,10 trimethyltricyclo[3:2:1:0 4 , ]decan-2-one with cyclopentadiene at -20*C using Et7 lCl catalyst To a stirred solution of cinnamate (0.101 g, 3.11 x 10~ 4 m) in dry CH2CI2 (ca 2 ml) at -78*C under argon, was added Et2AlCl (1.8 M 15 in toluene, 1 ml, 5.68 x 10" 4 m, 1.8 equiv.). To the resulting deep yellow/orange complex was added rapidly, via connector, pre-cooled, freshly cracked cyclopentadiene (1 g, 0.015m, 48 equiv.). The resulting solution was warmed to -20°C and within one minute the colour faded to pale green/yellow. The reaction was quenched and 20 worked-up as for examples 22(b) and 23(b), purified by flash chromatography (50 g Siθ2 » gradient elution n-hexane -> 10:1 n-hexane/ether -> 100% ether) which yielded a white crystalline solid (0.11 g, 92%) which was submitted for 360 MHz : H NMR. Only one isomer could be detected which had the following physical 25 properties; melting point 131-134 C (4:1 n-hexane/di-isopropylether), [©< ] 21 D —263.6 β , c-2.54 (CH 2 Cl2); M+-391.21473 C25H 29 N0 3 requires 391.214725; X H nmr(360 MHz, CDCI3) "57.29-7.14 (cm, 5H, Ph), 6.52 (dd,lH, J-5.63 and 3.19Hz, =CH) , 5.87 (dd, IH, J-5.63 and 2.75Hz, -CH), 4.57 (ddd, IH, J-9.89, 4,47 and 30 1.18Hz, CHN), 4.48 (dd, IH, J-9.78 and 1.59Hz, CHO), 4.22 (dd, IH, J-5.27 and 3.35Hz, CH), 3.56 (GS, IH, CH), 3.34 (dd, IH, J-5.26 and 1.68Hz, CH), 3.01-2.99 (cm, IH, CH)m 2.25 (t, IH, J-4.22Hz, CH), 1.98 (Gd, IH, J-8.72HZ, CH 2 ), 1.73-1.58 (dd, IH, J-8.69 and 1.69Hz, CH 2 , superimposed on cm, 2H), 1.45-1.39 (cm, IH), 1.25-1.14 (cm, 35 IH), 0.98 (S, 3H, CH 3 ), 0.97 (S, 3H, CH3), 0.94 (S, 3H, CH 3 ). 13 C nmr & 173.54, 153.91, 143.63, 140.08, 131.86, 128.24, 127.34, 125.85, 82.24, 57.66, 50.33, 49.24, 48.31, 48.09, 47.51, 47.31, 46.12, 26.18, 19.71, 19.43, 17.83, 13.64; tf max (Nujol) 2930, 1778 (2 x C-0), 1700 (C-C), 1338, 1225, 1212, 1060 cm -1 . Example 25 Cleavage of the cycloadduct formed in example 24 from the chiral auxiliary : chiral ester formation To a solution of benzyl alcohol (0.272 g, 2.52 x 10~ 3 m, 2 equiv.) in dry THF (ca 5 ml) at -78 β C under argon, was added n-butyllithium (1.6 M in hexanes, 1 ml, 1.6 x 10~ 3 m, 1.2 equiv.). The resulting solution was stirred at -78*C for c_a 30 minutes before a solution of cinnimate cycloadduct (0.5 g, 1.28 x 10 _3 m) in dry THF (ca 5 ml) was added dropwise. The reaction mixture was then allowed to stir at 0*C for 75 minutes and then at ambient temperature for 2 3/4 hours, by which time thinlayer chromatography indicated that all the starting material had been consummed. The reaction was quenched with NH4CI solution and concentrated in vacuo. The residue was diluted in H2O (ca 40 ml) and extracted into CH2CI2 (4 x ca 60 ml). The combined organic extracts were washed successively with saturated NaHC03, brine and dried over MgS04. Filtration and evaporation of the solvent in vacuo yielded an oil which was purified by column chromatography (60 g Siθ2, gradient elution n-hexane -> 19:1 -> 9:1 n-hexane/ether ->7:3 n-hexane/ether) yielded the chirally pure ester (0.333 g, 862). Further elution (1:4 n-hexane/ether yielded the recovered oxazolidinone (0.142 g, 57%). Physical data for ester; [o_ ] 21 χ)—121.1*, c-1.36 CH 2 Cl2., X H nmr (200 MHz, CDCI3) ξ) 7.47-7.25 (cm, 10H, 2 x Ph), 6.51 (dd, IH, J-5.65 and 3.21Hz, -CH), 6.17 (dd, J-5.65 and 2.75Hz, IH -CH)., 5.26 (d, IH, J-12.40HZ, CH 2 ), 5.17 (d, IH, J=12.42Hz, CH 2 ), 3.34 (GS, IH, CH), 3.15 (Gd, J-3.63HZ, CH), 3.14-3.12 (cm, 2H), 1.88 (Gd, IH, J=8.33Hz, CH 2 ), 1.67 (dm, J-8.68Hz, IH, CH 2 ), 13 C nmr (50.3 MHz, CDCI3) fc 173.76, 143.93, 138.89, 135.98, 134.17, 128.23, 127.83, 127.76, 127.20, 125.79, 65.95, 51.99, 48.02, 47.18, 46.95, 46.11; \> max (thin film) 2980, 1735, 1502, 1458, 1335, 1260, 1170 cm -1 . Example 26 Reaction of endo(9S.4R)-N-acryloyl-l-oxa-3-aza-8, 10, 10 trimethyltricyclo[3:2: 1:0 4 , 9 ]decan-2-one with benzonitrile oxide at O'C To a cooled (O'C), rapidly stirred solution of acrylate (0.10 g, 4.26 x 10- m) and benzohydroximmoyl chloride (0,068 g, 4.37 x 10~ 4 m, 1 equiv.) in CH2CI2 (ca 35 ml), a solution of triethylamine (0.049, 4.84 x 10~ m, 1.1 equiv.) in diethylether (ca 15 ml) was added over a period of 23 hours by means of a syringe pump. The solvents were then removed in vacuo and dissolved in CH2CI2 (c_a 50 ml), cooled successively with H2O (c_a 20 ml) and a little brine (ca 5 ml), NaHCθ3 solution, brine and dried over MgS04. Filtration and evaporation of the solvent in vacuo yielded the crude product which was analysed by 200 MHz H NMR and revealed the presence of two cycloadducts in a ration 4:1. Example 27 Use of endo-(9S.4R)-N-propionyl-l-oza-3-aza-8.1-.10- trimethyltricyclof3:2:l:0 4 . 9 ldecan-2-one in an asymmetric C_-bromination reaction and subsequent chiral O -azido propionate formation (a) Asymmetric a-bromination To a solution of imide (2.002 g, 7.97 x 10 -3 m) in dry CH2CI2 (ca 12 ml) at O'C under argon, was added a solution of fresh dibutylboron triflate (1M in CH 2 Cl2, 8.8 ml, 8.76 x 10~ 3 m, 1.1 equiv.), followed by Pr i EtN (1.24 g, 9.56 x 10" 3 m, 1.2 equiv.) in dry CH C1 2 (ca 7 ml). The resulting pale yellow solution was allowed to stir at O'C for one hour before being cooled to -78'C. The resultant boron enolate complex was added via connector to a pre-cooled (-78'C) slurry of N-bromosuccinimide (2.134 g, 0.012m, 1.5 equiv.) in dry CH 2 Cl2 (£ 10 ml). The resulting mixture was stirred at -78'C for 2 3/4 hours afterwhich thin-layer chromatography revealed that no starting material was present. The reaction was quenched with pH7 phosphate buffer (0.1M, c_a 20 ml) and the organic layer collected. The aqueous layer was further extracted with CH2CI2 (3 x c_a 50 ml) and the combined extracts were washed with brine and concentrated in vacuo. The residue was diluted in methanol ( ca 20 ml) and hydrogen peroxide (100 volumes, 12 ml) added with ice-cooling and stirring. This mixture was allowed to stir at -78'C for 90 minutes before being concentrated under high vacuum. The residue was diluted into H2O (c_a 30 ml) and extracted into CH2CI2 (3 x ca 89 ml). The combined extracts were washed successively with extracted NaHC03 solution, brine and dried over gS04- Filtration wand evaporation of the solvent in vacuo yielded a solid which was purified by flash chromatography (100 g Siθ2, gradient elution 20:1 n-hexane/ether -> 10:1 n-hexane/ether -> ether) yielded a white solid (1.4 g, 53%) which is the lower Rf diastereomer of example 16. (b) Conversion to oC-azido propionate To a solution of (2'R)-0<-broraocarboximide (0.6 g, 1.82 x 10" 3 m) in CH 2 C1 2 (ca 30 ml) was added NaN 3 (0.240 g, 3.69 x 10~ m, 2 equiv.) and a small amount of tertiarybutylammonium bromide (as phase transfer catalyst) in H2O (ca 50 ml). The resulting solution was stirred thoroughly at ambient temperature for 42.5 hours before the organic layer was collected and aqueous layer further extracted with CH 2 C1 (2 x 30 ml). The combined organic extracts were washed with brine and dried over MgS04. Filtration and evaporation of the solvent in vacuo yielded a white solid (0.524 g, 99%). l E nmr (200 MHz, CDCI3) S 4.97 (q, IH, J-6.89Hz, CH), 4.59-4.51 (cm, 2H, CHN and CHO), 2.30-2.12 (cm, IH, CH), 181-1.00 (d, 3H, J-6.9HZ, CH3 superimposed on cm, 4H, 2 x CH 2 ), 0.95 (S, 3H, CH3), 0.95 (S, 3H, CH3), 0.93 (S, 3H, CH3); i3 C nmr (50.3 MHz, CDCI3) £ 171.59, 153.47, 83.23, 57.52, 55.77, 49.34, 48.46, 47.30, 26.04, 19.65, 19.52, 17.80, 16.64, 13.57. This molecule can be cleaved from the auxiliary to generate c_-azido-propionic acid, which can be reduced to the homochiral c_-amino-carboxylic acid. This is obviously a general synthesis for any COA. Example 28 Use of endo-(9S,4R)-N-propionyl-l-oza-3-aza-8, 10.10- trimethyltricyclol.3:2: 1:0 4 . 1decan-2-one in asymmetric alkylation reactions (a) With benzyl bromide in the presence of Nal To a freshly prepared solution of LDA (0.11 g, 8.94 x 10" 3 m, 1.1 equiv.) in dry THF (5 ml) at -78'C under argon, was added a solution of carboximide (0.200 g, 7.97 x 10" 4 m) in dry THF (£ 8 ml) dropwise. The resulting solution was stirred at -78'C for one hour before freshly distilled benzyl bromide (0.513 g, 4.06 x 10- m, 5 equiv.), followed by Nal (pre-dried in vacuum oven, 0.146 g, 9.74 x 10 _4 m, 1.2 equiv.). The resulting solution was warmed to -8'C (KC1, H2θ(s)) and stirred overnight at that temperature. The reaction was quenched with NH4CI solution and concentrated in vacuo. The residual oil was diluted with H2O (c_a_ 30 ml) and extracted into CH2CI2 (4 x ca 60 ml). The combined organic extracts were washed successively with saturated NaHCC>3, brine and dried over MgSθ4- Filtration and evaporation of the solvent in vacuo yielded an oil which was purified by dry flash chromatography (60 g Siθ2, gradient elution n-hexane -> 4:1 n-hexane/ether -> 1:1 n-hexane/ether -> ether) yielding a white solid (0.218 g, 80%); melting point 100.5-101.5'C (MeOH); [β- ] 21 D —63.40*, c-2.12 (CH 2 C1 2 ); Found C, 74.0, H, 8.16; N, 412. C21H27NO3 requires C, 73.87; H, 7.97; N, 4.10; X H nmr (200 MHz, CDCI3) S 7.30-7.12 (cm, 5H, Pb), 4.55 (ddd, IH, J-9.85, 4.27 and 1.0Hz, CHN), 4.38 (dd, IH, J-9.64 and 1Hz), 4.14 (m, IH), 3.12 (dd, J-13.18 and 7.23Hz, IH, CH 2 ), 2.57 (dd, IH, J-13.19 and 7.76Hz, CH 2 ), 2.17 (t, J=4.18Hz, IH, CH), 1.52-1.11 (d, J-6.76HZ, 3H, CH3 superimposed on cm, 4H, 2 x CH2), 0.93-0.91 (2 x S, 9H, CH3); 13 C nmr (50.3 MHz, CDCI3) S 176.38, 153.76, 139.10, 129.04, 128.06, 126.04, 82.16, 57.75, 49.16, 48.23, 47.47, 39.53, 39.41, 26.05, 19.69, 19.01, 17.83, 16.47, 13.64. tf max 1760, 1680 cm-*. This was the only isomer c'etected. ( ) With allyl bromide This was constructed in the same way as for benzyl bromide, but without the use of Nal, and the reaction was quenched after four hours. Column chromatography yielded colourless crystals (70%), melting point 79-89'C (aqueous MeOH). Found C, 69.7; H, 8.71; N, 4.73, C 17 H 2 5N0 3 requires C, 70.07, H, 8.65; N, 4.81; : H nmr S 5.79 (IH, ra), 5.12-4.96 (2H, m), 4.60-4.49 (2H, m), 3.88 (IH, m), 2.51 (IH, m), 2.27 (IH, m), 2.15 (IH, ra), 1.70-1.55 (2H, m) 1.39 (IH, m), 1.20 (IH, m), 1.20 (IH, m) 1.15 (3H, d, J-6Hz), 0.98 (3H, S), 0.97 (S, 3H), 0.96 (S, 3H) . Again, this was the only isomer detected. Example 29 Preparation of Endo-(9S.4R)-l-oxa-3-aza-8.10.10.-triraethyltricycloT3.2.1.0 , 9 1- decan-2-thione A solution of the product of example (6a) (0.5g,2.56mm) and phosphorus pentasulphide (0.23g,0.513mm) was refluxed in sodium dried toluene (20ml) under argon. After an initial 2 hours the reaction mixture was monitored hourly by tic; then left overnight and was stopped after 19 hours. The reaction mixture was then filtered, washed (dry ether) and evaporated in vacuo to yield a light brown solid (0.66g). This was dissolved in CH2CI2 (30ml), washed with H2O (2x20ml), dried with magnesium sulphate and filtered. Evaporation of the mother liquor in vacuo yielded endo-(9S,4R)-l-oxa-3-aza-8,10,10-trimethyltricyclo[3.2.1.0 , 9 ]-decan -2-thione as a colourless, crystalline solid (0.2g,40%); m.p. 190-192'C; M + 211.10308; C u H 17 N0S requires 211.10321; tf max 3180 (N-H), 2960 (C-H), 1520 (C-N), 1380 (C-C), 1270 (C-0), 1175 (C-S); ^max (EtOH) ( & 246nm (20.9xl0 4 ); A H nmr (200MHz) S 0.91,0.96,0.98 (3s,9H,3xCH 3 ), 1.24-1.49 (m,2H,lxCH 2 ), 1.55-1.74 (ra,2H,lxCH 2 ), 1.95-1.99 (t,lH,lxCH), 4.33-4.41 (dd,lH,CH), 4.85-4.90 (dd,lH,CH), 7.93 (s.lH.NH); 13 C nmr (50MHz) $ 189.82 (C-S,q), 93.23 (t), 59.95 (t), 49.66 (q), 48.47 (t), 26.76 (d), 20.37 (d), 19.79 (s), 18.10 (s), 13.87 (s). Example 30 Preparation of Endo-(9S,4R)-3-Octadecoxycarbonyl-l-oxa-3-aza-8, 10. 10-trimethyltricycloT3.2.1.0 4 . 9 1decan-2-one Octadecyl chloroformate (2.29g, 6.91 x 10- m) in anhydrous diethyl ether (20 ml) was added dropwise to a rapidly stirred suspension of the sodium salt of the compound of Example 6(a) (1.50g;6.91 x 10 _3 m) in anhydrous diethyl ether (20 ml) under argon at 20 * C. The reaction mixture was stirred for a further 60 minutes, washed once with saturated sodium bicarbonate solution and then with water, dried (MgSθ4), and evaporated in vacuo to yield a colourless solid (3.19g, 94%) which was further purified either by recrystallizaion from methanol (2.07g, 61%) or by medium-pressure liquid chromatography (Siθ2; petroleum ether: ethyl acetate gradient 10:l-> 2:1) (3.01g; 89%); m.p. 4-45'; [<*] 2 D - - 16.3', c = 3.22 (ethanol); l E nmr (200MH Z , CDCI3) Sθ.83 (ra, 3H, - CH 2 CH 3 ), 0.94 (s, 3H, CH3), 0.96 (s, 3H, CH3), 1.23 (m, 32H,-C 16 H 32 -), 1.7 (m,4H), 2.18 (m,lH), 4.23(m, 2H, -0CH 2 -), 4.47 (s.lH, CHN), 4.48 (s,lH,CH0); 13 C(50.3 MH Z ,CDC1 3 ) & 152.5 (C-0), 151.0 (C-0), 81.8 (CHO), 67.0 (-0-CH 2 ), 57.9 (CHN), 49.3 (quart.C), 48.3 (CH), 31.8 (CH 2 ), 29.5 (CH 2 ), 28.9 (CH 2 ), 28.4 (CH 2 ), 26.1 (CH 2 ), 25.5 (CH 2 ), 25.5 (CH 2 ), 22.5 (CH 2 ) 19.8 (CH3), 19.6 (CH 2 ), 17.9 (CH3), 13.9 (CH3), 13.7 (CH 3 ); max (thin film) 1825, 1803 (sh), 1731 (C-0) cm -1 . Example 31 Preparation of f(4R.9S)exol-(+)-l-Oxa-3-aza-8-ρhenyl-sulphonylmethyl-10. 10-dimethyltricvclor3.2.1.0-_ -1-decan-2-one t(2R)-exo]-(+)-l-Phenylsulphonylmethyl-7,7-dimethylbicyclo[2.2.1] heptan-2-ol was prepared from (lS)-(+)-10-camphorsulphonic acid as described in Tetrahedron Letters .25 , (1984) 5889. This was converted into the corresponding 2-chloroformate and then the 2-azidoformate by the method described in Examples 1 and 3. The azidoformate had the following analysis: m.p. 117.5' (decomp.); [*.] 21 . 5 D - -20.1', c-2.52 (EtOH); FAB-MS (M+l) + 364.13311 C 17 H22N3θ 4 S requires 364.13309; X H nmr (200 MHz, CDCI3) 80.81 (s, 3H, CH3), 0.89 (s, 3H, CH3), 1.15 (m, IH), 1.5-2.0 (m, 6H), 2.92 (d, IH, CHHS0 2 , J - 14.03 Hz), 3.45 (d, IH, CHHS0 2 , J - 14.03 Hz), 4.90 (ra, IH, CHO), 7.5-7.7 (m, 3H, aromatics), 7.95 (ra, 2H, aromatics). A solution of [(2R)-exo]-(+)-l-phenylsulphonylmethyl-7,7- dimethylbicyclo[2.2.1]heptan-2-azidoformate (4.5g, 1.23xl0" 2 m) in 1,1,2,2-tetrachloroethane (TCE) (50ml) was added dropwise over 30 minutes to vigorously boiling TCE (450ml) under argon. When the addition was complete, the solvent was removed in vacuo to yield a brown oil, which upon trituration with diethyl ether (500ml) yielded a light brown solid (3.4g). The product was further purified by recrystallisation from ethyl acetate (3.27g, 79%), to give the desired product [(4R,9S)-exo]-(+)-l-Oxa-3-aza-8-phenyl- sulphonylmethyl-10,10-dimethyltricylco[3.2.1.0 4 » 9 ]decan-2-one, which had the following analysis: m.p. 211-212'C; [C*] 21 . 1 ]) - -63.2', c-2.82 (EtOH); FAB-MS (M+l) + 336.12694. C 17 H22N04S requires 336.12694; H nmr (360 MHz, CDC1 3 ) Sθ.86 (s, 3H, CH3), 0.97 (s, 3H, CH 3 ), 1.30 (m, IH), 1.54 (m, IH), 1.73 (m, IH), 1.83 (m, IH), 1.97 (m, IH), 2.95 (d, IH, CHHS0 2 ), J - 13.8 Hz), 3.48 (d, CHHS0 2 , J - 13.8 Hz), 3.77 (d, IH, CHN, J - 8.21 Hz), 4.93 (d, IH, CHO, J - 8.13 Hz), 6.62 (bs, IH, NH), 7.51-7.55 (m, 2H, 3 aromatics), 7.59-7.64 (m, IH, 4 aromatics), 7.91-7.94 (m, 2H, 2 aromatics); 13 C nmr (50.3 MHz, CDCI3) & 159.81 (C-0), 140.68 (Cx-CeHs), 133.61(C 4 -C 6 H 5 ), 129.17 (C 6 H 5 ), 127.57 (C 6 H 5 ), 84.12 (CHO), 60.43 (CHN), 53.72 (CH 2 S0 2 ), 48.98 (quart. C), 47.18 (CH), 27.37 (CH 2 ) 24.63 (CH 2 ), 23.27 (CH 3 ), 19.16 (CH3); \. max (KBr) 3342 (br, NH), 1760 (s, C-0), 1717 (s, NH), 1320, 1160, 1138 (s, S0 2 )cm _1 . Example 32 This example describes the alkylation of a compound of formula 1(a) in which Y is a C 2 H5CO- group to form a compound with a new optically active centre adjacent to the carbonyl group. A solution of imide of part (a), Example 12 (300 mg, 1.2 ml) in THF (5 ml) was added slowly to a solution of LDA (1.3 mm) in THF (2 ml) at -78'C. After stirring for lh at -78'C the mixture was warmed to -10'C and a solution of the alkylating agent (3.5 ml) in THF (2 ml) was added. The mixture was kept at -10'C for 4h after <.hich time reaction was complete as monitored by tic. The mixture was quenched using saturated aqueous ammonium choride and, following standard aqueous workup purification of the residue by flash chromatography gave the product(s). (i) reaction with iodoethane gave a single diastereoisomer (17 mg, 6%) as a colourless solid. Found: M + , 279.182. C16H25NO3 requires M, 279.183); : H nmr S 4.63-4.45 (2H, m), 3.69 (IH, sextet, J-7Hz), 2.30 (IH, t, J=4Hz), 1.85-1.20 (6H, m), 1.15 (3H, d, J=H7z) 0.97 (3H, s), 0.96 (3H,s) 0.95 (3H,s), 0.93 (3H, t, J-7Hz). This material was not characterised further (see above), (ii) reaction with allyl bromide gave a mixture of two diastereoisomers ratio >10:1 (210 rag, 70%) as colourless crystals melting point 79-80'C (aqueous methanol) Found: C, 69.7; H, 8.71; N, 4.73. C17H25NO3 requires C, 70.07; H, 8.65; N, 4.81; max (Nujol) 1770, 1680 cm -1 ; m/z (ei) 291 (M + , 100%), 196 (20%), 135 (18%); X H nmr 55.79 (IH, m), 5.12-4.96 (2H, m), 4.60-4.49 (2H, m), 3.88 (IH, m) 2.51 (IH, m), 2.27 (IH, m), 2.15 (IH, m), 1.70-1.55 (2H, m), 1.39 (IH, m), 1.20 (IH, m), 1.15 (3H, d, J-6Hz), 0.98 (3H, s) 0.97 (3H, s) 0.96 (3H, s). (iii) reaction with PhC^Br gave a single diastereoisomer (172 rag, 42%) as colourless crystals melting point 100-101.5'C (methanol) Found: C, 74.0; H, 8.16; N, 4.12. C21H27NO3 requires C, 73.87; H, 7.97; N, 4.10; >)max(Nujol) 1760, 1680 cm -1 ; m/z (ei) 341 (M + ), 196, 177, 135, 118, 91; X H nmr & 7.26-7.13 (5H, m), 4.55 (IH, ddd, J-10.6Hz); 4.47 (IH, dd, J-lOHz), 4.17 (IH, sextet, J-7Hz), 3.14 (IH, dd, J-13.7Hz), 2.59 (IH, dd, J-13.7Hz), 2.19 (IH, t, J, 4Hz), 1.63-1.22 (3H, m), 1.15 (3H, d, J-7Hz), 0.95 (3H, s), 0.93 (6H, br.s), 0.67 (IH, ra). Example 33 (a) Preparation and Physical Data for ,(9S, 4R)-endo]-3- (N-benzyloxycarbaraate)-l-oxa-3-aza-8.10.10-trimethyl-tricyclo r3.2.1.0 4 . 9 1decan-2-one. N-Chloroformyl derivative of example 6(a) (2.57 g, 9.98 x 10 _3 m) in anhydrous dichloromethane (20 ml) was added dropwise to a stirred suspension of freshly sublimed . -benzylhydroxylaraine hydrochloride (sublimed 80'C/0.1 mm Hg) (..59 g, 9.98 x 10" 3 m) and pyridine (1.57 g, 1.99 x 10 "2 m) in dichloromethane (20 ml) at O'C under argon. The reaction mixture was stirred at room temperature overnight and evaporated to dryness. The product was obtained as a white crystalline solid after flash chromatography (2.78 g, 81%). This compound will crystallize from diethylether : n-hexane. Melting point 86-87'C; [< ] D =-117°, c=2.0 (CH 2 C1 2 ); FAB-MS (M+l) + 345.18144 C 19 H25N 2 ° requires 345.18142; X H nmr (360 MHz, CθCl 3 ) S 0.91 (S, 3H, CH 3 ), 0.93 (S, 3H, CH3), 0.94 (S, 3H, CH 3 ), 1.2 (m, IH, CH), 1.35 (m, IH, CH), 1.6 (m, 2H, CH 2 ), 2.29 (m, IH, CH), 4.45 (m, 2H, CHO, CHN), 4.90 (S, 2H, PhCH 2 0), 7.3-7.4 (m, 5H, aromatics), 10.17 (bs, IH, NH); 13 C nmr (50.3 MHz, CDCI3) S 155.43 (C-0), 115.52 (C-0), 134.92 (^-aromatic), 128.96 (CH), 128.50 (CH), 128.33 (CH), 84.13 (CHO), 78.69 (0CH 2 ), 57.30 (CHN), 49.29 (quart.c), 48.26 (quart.c), 47.94 (CH), 26.16 (CH 2 ), 19.70 (CH , CH3), 17.84 (CH3), 13.61 (CH3); 3 max (thin film) 3320 (m, NH), 1760 (S), 1715 (S, C-0, NH) cm -1 . (b) Preparation and Physical Data for T(9S.4R)-endo1-3- (N-hydroxycarbamate)-l-oxa-3-aga-8.10.10-trimethyltricyclo T3.2.1.0 4 . 9 1decan-2-one. The N-benzyloxy derivative (2.57 g, 6.59 x 10 "3 m) and 1 drop of glacial acetic acid in methanol (50 ml) was added to 10% palladium on charcoal (0.2 g) suspended in methanol (5 ml). The resultant mixture was stirred under 1 atmosphere of hydrogen for 5 hours at room temperature and then filtered through a celite pad and evaporated in vacue to yield a white solid which was purified by flash chromatography (1.59 g, 95%). This compound will crystallize as needles from dichloromethane : petroleum ether 40-60. Melting point 120'C-121'C; [o ] D —135.9', c-1.8 (ethanol); FAB-MS (M+l) + 255.13449 C 12 H 19 N 2°4 requires 255.13447; X H nmr (200 MHz, CDCI3) S 0.92 (S, 3H, CH3), 0.95 (S, 6H, 2 x CH3), 1.20 (m, 2H, CH 2 ), 1.57 (m, 2H, CH 2 ), 2.25 (m, IH, CH), 4.58 (m, 2H, CHO, CHN), 8.36 (bs, IH, OH), 10.1 (bs, IH, NH); 13 C nmr (50.3 MHz, CDCI3) $155.42 (C-0), 153.56 (C-0), 84.28 (CHO), 57.40 (CHN), 49.34 (quart.c), 48.32 (quart.c), 47.81 (CH) , 26.11 (CH ), 19.68 (CH 2 , CH3), 17.85 (CH3), 13.64 (CH 3 ); vmax (evaporated film) 3449 (b, NHOH), 1755 (2 x C=0) cm -1 .

Claims: Claims 1. A compound of the general formula 1(a) and/or 1(b) and/or 1(c):- Ka) Kb) Kc) in which R! represents a methyl group or a group of the general formula -CH 2 .S0 2 .R 2 or -CH2.SO2.NR 2 R 3 , in which each of R 2 and R 3 independently represents an alkyl, cycloalkyl or optionally substituted phenyl or phenalkyl group; each of R 4 , R 5 and R° independently represents a hydrogen atom or a methyl group; X represents a group of formula C CH3)2 or, when both of R^ and R° represent methyl groups, also represents a group of formula CH 2 ; Q represents an oxygen or sulphur atom; and Y represents a hydrogen atom, an alkali metal atom or a group of the general formula -COA in which A represents a halogen atom or an alkyl or alkoxy group optionally substituted by a phenyl, cycloalkyl, alkoxy or alkylcarbonyl group. 2. A compound according to claim 1 in which the optionally substituted phenyl or phenalkyl group R 2 and/or R 3 carries one or more inert substituents. 3. A compound according to claim 2 in which the substituents are selected from halogen atoms and alkyl, alkoxy, haloalkyl, haloalkoxy, nitro, alkylcarbonyl and alkoxycarbonyl groups. 4. A compound according to claim 3 in which the alkyl moiety has from 1 to 4 carbon atoms. 5. A compound according to any of claims 2 to 4 in which the substituted phenyl group has up to 3 substituents. 6. A compound according to claim 2 in which the alkyl moiety in the phenalkyl group has from 1 to 4 carbon atoms. 7. A compound according to any of claims 1 to 6 in which the alkyl group R 2 and/or R 3 has up to 20 carbon atoms. 8. A compound according to claim 7 in which the alkyl group R 2 and/or R 3 has 4 to 8 carbon atoms. 9. A compound according to any of the preceding claims in wiich the alkyl or alkoxy group A has up to 30 carbon atoms. 10. A compound according to claim 1 or claim 9 in which the cycloalkyl substituent on an alkyl or alkoxy group A is a cyclopentyl or cyclohexyl group. 11. A compound according to claim 1 in which the alkoxy or alkylcarbonyl substituent A has up to 6 carbon atoms in the alkyl moeity. 12. A compound according to claim 1 in which Q represents an oxygen atom. 13. A compound of general formula:- 38 in which R! represents a methyl group or a group of the general formula -CH 2 .S0 .R 2 or -CH 2 .Sθ2.NR 2 R 3 , in which each of R 2 and R 3 independently represents an alkyl, cycloalkyl or optionally substituted phenyl or phenalkyl group; each of R 4 , R- and R° independently represents a hydrogen atom or a methyl group; Z represents an -N3 group or a group of the general formula -NH.0.S02.R^, in which R^ represents an optionally substituted phenyl group. 14. A process for the preparation of a compound according to any of claims 1 to 12 which comprises inducing ring closure in a compound according to claim 13. 15. A process for separating enantiomers of a compound capable of reacting with a compound according to any of claims 1 to 12 comprising contacting a mixture of said enantiomers with said compound and separating the resulting components of the mixture. 16. A process for generating a compound having an optically active carbon atom from a compound having an optically inactive carbon atom comprising reacting a compound according to any of claims 1 to 12 in which A is an optionally substituted alkyl group with an alkylating agent. 17. A process according to claim 16 in which the alkylating agent is an aldehyde, ketone, keto-acid, alkyl halide or epoxide. 18. Compounds containing an optically active carbon atom whenever prepared according to claims 16 or 17.

Inventors: BANKS MALCOLM ROBERT, CADOGAN JOHN IVAN GEORGE, DAWSON IAN MICHAEL, GOSNEY IAN, HODGSON PHILIP KENNETH GORDON, BANKS, MALCOLM, ROBERT, CADOGAN, JOHN, IVAN, GEORGE, DAWSON, IAN, MICHAEL, GOSNEY, IAN, HODGSON, PHILIP, KENNETH, GORDON
Applicants: BRITISH PETROLEUM CO PLC, THE BRITISH PETROLEUM COMPANY PLC
Application year: 1991
Main classification: C07C311
IPC codes: C07C247, C07C309, C07C311, C07C317, C07D263, C07D265