Preparation of beta-lactam compounds, and intermediates therefor.

摘要

A process for preparing a beta -lactam compound of the formula (I): which comprises cyclization of an azetidinone derivative of the formula: in which R<1> is hydrogen, alkyl which is optionally substituted, or amino which is optionally substituted; R<2> is a carboxy - protecting group; and X is alkylene which is optionally intervened by -O- or -S-, and/or which is optionally substituted; and R<3> is aryl which is optionally substituted.