tert.-butyl 4-<3(R)-benzoylamino-2-azetidinon-4(R)-yloxy>-2-diazo-3-oxo-butanoate                                                                                                                                                              在
                                                                                                                                         
汞                                                                                                                                                                                                                               氮   、                                                                                                  silica gel   、                                                                                                  
toluene-ethyl acetate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         Benzene tetrahydrofuran                                                                                  为溶剂,
                                                                                                                                                    反应 1.0h,
                                                                                                                以12 mg (17%) of the title compound were obtained as a colorless rigid foam的产率得到tert.-butyl (6R,7R)-7-benzoylamino-3-hydroxy-8-oxo-5-oxa-1-azabicyclo<4.2.0>oct-2-ene-2-carboxylate