Beta-lactam compound and process for production thereof.

摘要

A cephem compound characterised in that it corresponds to the following general formula (III): wherein R1 represents hydrogen or -A-B (wherein A represents oxygen or sulfur and B represents (a) an acyl group, (b) an optionally substituted heterocyclic group containing at least one heteroatom selected from oxygen, nitrogen and sufur, or (c) an optionally substituted carbamoyl group); R2 represents a protective group for the hydroxyl or carboxyl group; R3 and R4 independently represent hydrogen or C1-C4 alkyl, or R3 represents hydrogen and R4 represents C1-C4 alkoxyl; and Y represents chlorine or bromine is disclosed, as is the production thereof under mild conditions. The compound is useful as an intermediate for the synthesis of beta -lactam antibiotics of a new class.