6-Alkylidene penems.

摘要

Compounds of the general formula I: <CHEM> and their pharmaceutically acceptable salts and in vivo hydrolysable esters, in which one of R<1> and R<2> denotes hydrogen, the other of R<1> and R<2> denotes an unsubstituted or substituted non-aromatic heterocyclyl group bonded through a carbon atom thereof, and R<3> denotes hydrogen or an organic group are novel compounds with beta -lactamase inhibitory and anti-bacterial properties.