Synthesis, Reactivity, and Antibacterial Activity of gem -Difluoroalkene, Difluoromethyl, and Trifluoromethyl β-Lactams.

New gem -difluoroalkenes were synthesized by the dehydrofluorination of the corresponding 4-CF 3 -β-lactams. An unexpected rearrangement mechanism of the ester moiety dependent on a stabilizing negative charge was observed. Hydrogenation to 4-CHF 2 -β-lactams was successful from gem -difluoro-β-lactams.