Intermediates and a stepwise process for the conversion of D-methionine or certain of its derivatives to optically active compounds of the formula ##STR1## wherein R is (C.sub.1 -C.sub.3)alkyl, phenyl or tolyl. The latter compounds are in turn useful as an intermediate in the preparation of penem antibiotic 5R,6S-6-(1R-hydroxyethyl)-2-(1R-oxo-3S-thiolanylthio)-2-penem-3-carboxylic acid and corresponding pharmaceutically acceptable salts and esters.
将
D-蛋氨酸或其某些衍
生物转化为光学活性化合物的中间体和逐步过程,其中化合物的
化学式为##STR1## 其中R为(C.sub.1-C.sub.3)烷基,苯基或
甲苯基。这些化合物反过来又可用作制备青霉烷类抗生素5R,6S-6-(1R-羟乙基)-2-(1R-氧代-3S-
硫代基
硫基)-2-青霉烷-3-
羧酸及相应的药用盐和酯的中间体。