Process for preparing 2-substituted 2-penem-3-carboxylic acid compounds and intermediates

摘要

PROCESS AND INTERMEDIATES FOR THE PREPARATION OF PENEM DERIVATIVES Certain substituted-2-penem-3-carboxylic acid compounds, and pharmaceutically-acceptable salts thereof, can be prepared from the appropriate xanthate or trithiocarbonate by desulfurization, followed by halogenation and ring closure. The corresponding desulfurized and halogenated intermediates are disclosed.