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
lithium bromide 作用下,
以
正戊烷 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-bromo-acetic acid 2,2,2-trichloroethyl ester