| 摘要 |
A process for the preparation of a pharmaceutically active compound in a stereospecific form of the formula <CHEM> or a pharmaceutically acceptable salt or ester thereof, like an alkali metal salt or an alkaline earth metal salt or a pivaloyl ester, wherein R1 represents an optionally substituted aryl group such as a phenyl or naphthyl group optionally included in a heterocyclic ring system, which is optionally substituted, or represents a heteroaromatic ring system containing in addition to carbon atoms one or more atoms selected from nitrogen, sulphur and oxygen, this ring system being optionally substituted, which comprises subjecting a compound of the formula <CHEM> wherein R2 is an ester residue and preferably an alkyl group optionally substituted, to the action of a micro-organism having the ability for stereoselective hydrolysis of compound (II) into compound (I), having at least 80% by weight the S-configuration, and if desired converting compound (I) into the pharmaceutically acceptable salt or ester thereof. |
