| abstract |
A compound of general formula I(a) and/or I(b) and/or I(c), in which R1 represents a methyl group or a group of the general formula -CH¿2?.SO2.R?2¿ or -CH¿2?.SO2.NR?2R3¿, in which each of R?2 and R3¿ independently represents an alkyl, cycloalkyl or optionally substituted phenyl or phenalkyl group; each of R?4, R5 and R6¿ independently represents a hydrogen atom or a methyl group; X represents a group of formula C(CH¿3?)2 or, when both of R?5 and R6¿ 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. The compounds are bicyclic optically active compounds and are useful in the synthesis of optical isomers and separation of optical isomers from mixtures. |