(5R)-6-(E)-benzyloxycarbonylmethylene-3,3-dimethyl-7-oxo-(5rH)-4-thia-1-aza-bicyclo[3.2.0]heptane-2c-carboxylic acid 2,2,2-trichloro-ethyl ester 以
二氯甲烷 为溶剂,
生成 (1
S)-3',3'-dimethyl-7'-oxo-3,3-diphenyl-(1
rC5',5'
t'
H,6'
r'
C2)-spiro[cyclopropane-1,6'-(4-thia-1-aza-bicyclo[3.2.0]heptane)]-2
t,2'
t'-dicarboxylic acid 2-benzyl ester 2'-(2,2,2-trichloro-ethyl) ester