1,1,3,3-tetramethylguanidinium formate 、 4-Bromo-3-bromomethyl-2-[(2S,3R)-2-chloro-4-oxo-3-(2,2,2-trichloro-ethoxycarbonylamino)-azetidin-1-yl]-but-2-enoic acid methyl ester 以
氯仿 为溶剂,
以26%的产率得到2-[(2S,3R)-2-Chloro-4-oxo-3-(2,2,2-trichloro-ethoxycarbonylamino)-azetidin-1-yl]-4-formyloxy-3-formyloxymethyl-but-2-enoic acid methyl ester