A sequential reductive 1,2-elimination-addition-cyclization of 3,4-disubstituted butenoates derived from penicillin is performed successfully by treatment with alkenyltin, copper(I) chloride and 2,2′-bipyridine (bpy) in N-methyl-2-pyrrolidinone (NMP) to afford 3-alkenyl-Î3-cephems.
                                    通过用链烯基
锡、
氯化亚铜和 
2,2'-联吡啶 (bpy) 在 N-甲基- 溶液中处理,成功地对源自
青霉素的 3,4-二取代
丁烯酸酯进行连续还原 1,2-消除-加成-环化反应。 
2-吡咯烷酮 (
NMP) 提供 3-烯基-α3-头孢烯。