7 alpha -Methoxycephalosporins

摘要

A 7 alpha -methoxycephalosporin represented by the general formula: <IMAGE> wherein R1 represents a hydrogen atom or a carboxyl-protecting group; R2 represents an organic group linked to the carbon atom through an oxygen or sulfur atom; R3 represents a lower alkyl group; n is 0, 1 or 2; A represents a hydrogen atom or a substituted or unsubstituted alkyl group; and B represents a substituted or unsubstituted alkyl, cycloalkyl, cycloalkenyl, cycloalkadienyl or heterocyclic group, and a salt thereof. These compounds have a broad antibacterial spectrum, high resistance to beta -lactamase produced from bacteria, and an effective antibacterial activity against clinical isolates of bacteria.