p-nitrobenzyl (2R)- and (2S)-2-<(3R,4R)- and (3R,4S)-4-chloro-3-(p-nitrobenzyloxycarbonyloxymethyl)-2-oxoazetidin-1-yl>-4,4-dimethyl-3-oxopentanoates 在
potassium tert-butylate 作用下,
以
四氢呋喃 为溶剂,
反应 1.0h,
生成
p-nitrobenzyl (-)-(5S,6R)-3-tert-butyl-6-(p-nitrobenzyloxycarbonyloxymethyl)-7-oxo-4-oxa-1-azabicyclo<3.2.0>hept-2-ene-2-carboxylate