Transformations of penicillins: reactions of penam S-oxides with N-chloro-N-sodiocarbamates

Abstract

Penicillanate (S)-S-oxides reacted with ethyl N-chloro-N-sodiocarbamate to give 6α-ethoxyformamido-derivatives together with the corresponding 6-epi-penicillanate, an intermediate in the formation of the former product. The (R)-S-oxides reacted with N-chloro-N-sodiocarbamate to give 6α-alkoxyformamido-derivatives, together with 6,6-bis(alkoxyformamido)penam (R)-S-oxides, which were further transformed into cephalosporanates. Mechanisms for these substitution reactions are discussed.