α-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0]heptyl)-α-chloroacetic acid 2,2,2-trichloroethyl ester                                                                                                                                                              在
                                                                                                                                                                                 
sodium                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
苯                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 
α-(2-carbo-tert.-butyloxy-3,3-dimethyl-7-oxo-4-thia-2,6-diaza-6-bicyclo[3,2,0]heptyl)-α-(tri-n-butyl-phosphoranylidene)-acetic acid 2,2,2-trichloroethyl ester