PROCESS FOR PRODUCING CARBEPENEME DERIVATIVES AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM AS ACTIVE COMPONENT

摘要

Compounds of formula (I): (I) wherein: one or both of R1 and R2 are selected from a variety of organic groups; R3 is an optionally substituted heterocycle; and R4 is hydrogen or optionally substituted alkyl or alkoxy. and salts and esters thereof have valuable antibiotic activity.