叔-丁基苯乙酸酯 、
(6R)-7t-isocyanato-3-methyl-8-oxo-(6rH)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid 4-nitro-benzyl ester 生成 (6
R)-7
t-((Ξ)-2-
tert-butoxycarbonyl-2-phenyl-acetylamino)-3-methyl-8-oxo-(6
rH)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid 4-nitro-benzyl ester