1-(4-nitrobenzyl) 3-[(3S,4S)-3-benzyloxycarbonylamino-2-azetidinon-4-yl]methylthio-2-oxoglutarate 、
N,N'-二环己基碳二亚胺 生成 (4-nitrophenyl)methyl (1R,4S,5S,8R)-3,10-dioxo-4-(phenylmethoxycarbonylamino)-11-oxa-6-thia-2-azatricyclo[6.3.0.02,5]undecane-1-carboxylate