BETA-LACTAM COMPOUNDS, THEIR PREPARATION AND USE

摘要

The present invention relates to the preparation of compounds of the formula: wherein CO2R1 is a free, salted or esterified carboxyl group, n is 0 or 1, and R2 is hydrogen or an acyl group or a group of the sub-formula (a): R3O3S (a) wherein R3 is a salting ion or a methyl or ethyl group, with the proviso that when R2 is a group of the formula (a), the compound has cis stereochemistry about the alpha -lactam ring; which have been found to possess antibacterial and alpha -lactamase inhibitory activity.