MANUFACTURE OF PENEM DERIVATIVE

摘要

Certain 2-substituted-2-penem-3-carboxylic acid compounds and pharmaceutically-acceptable salts thereof can be prepared from the appropriate xanthate or trithiocarbonate by desulfurization and addition of an electrophilic sulfur compound followed by halogenation and ring closure. The corresponding desulfurized and halogenated olefinic intermediates are disclosed.