Azetidinyl acetic acid esters

摘要

Novel diastereomers of the Formula I which are useful as intermediates in the preparation of thienamyan, are prepared in a process which comprises removing the ethylene ketal group from a compound of the general Formula III [wherein R<1> is hydrogen or (as an amide protecting group) a phenyl or benzyl group optionally substituted by one or more methoxy group(s)] and reducing the new compound of the general Formula thus obtained.