AZETIDINONE DERIVATIVES

摘要

Compounds of formula (I): [in which: R<1> is hydrogen or a hydroxy-protecting group; R<2> is alkyl, alkoxy, halogen, optionally substituted phenyl or optionally substituted phenoxy; R<3> is optionally substituted pyridyl, optionally substituted quinolyl or phenyl group which has a substituent of formula -CYNR<5>R<6>, where Y is oxygen or sulphur, and R<5> and R<6> are each alkyl, aryl or aralkyl, or R<5> and R<6> and the nitrogen to which they are attached together form a heterocyclic group; R<4> is hydrogen or an amino-protecting group; and Z is sulphur or oxygen]; are valuable intermediates in the preparation of carbapenem compounds and retain a desirable configuration during conversion to such carbapenem compounds.