1,1,3,3-tetramethylguanidinium acetate 、 (E)-3-Bromomethyl-2-[(2S,3R)-2-chloro-4-oxo-3-(2,2,2-trichloro-ethoxycarbonylamino)-azetidin-1-yl]-4-formyloxy-but-2-enoic acid methyl ester 以
氯仿 为溶剂,
以25%的产率得到(E)-4-Acetoxy-2-[(2S,3R)-2-chloro-4-oxo-3-(2,2,2-trichloro-ethoxycarbonylamino)-azetidin-1-yl]-3-formyloxymethyl-but-2-enoic acid methyl ester