Processes for removing allyl groups.

摘要

A process for removing an allyl group from a penem compound of formula (I), <CHEM> wherein R<1> is an allyl group which may have a substituent and m denotes 0 or 1, is disclosed. The process comprises reacting said penem compound of formula (I) with a cyclic 1,3-diketone compound or its alkali metal enolate. The carboxylic allyl ester changes to an alkali metal salt of carboxylic acid at the same time the removal of the allyl group from the carboxylic allyl ester occurs, giving a high purity alkali metal salt in a high yield without requiring any additional processes.