(Ξ)-hydroxy-[(3
R)-2-oxo-4
c-(2-oxo-propylsulfanyl)-3
r-(2-phenoxy-acetylamino)-azetidin-1-yl]-acetic acid 4-nitro-benzyl ester 生成
(5R)-3ξ-acetyl-7-oxo-6t-(2-phenoxy-acetylamino)-(5rH)-4-thia-1-aza-bicyclo[3.2.0]heptane-2ξ-carboxylic acid 4-nitro-benzyl ester