(2R,5S,6R,7S)-3-Methylene-5,8-dioxo-7-(2-phenoxy-acetylamino)-5λ
4-thia-1-aza-bicyclo[4.2.0]octane-2-carboxylic acid 3-nitro-phenyl ester 在
三苯基膦 作用下,
以
二氯甲烷 为溶剂,
以43%的产率得到(1R,5S)-6-(4-Methyl-2-oxo-2,5-dihydro-furan-3-yl)-3-phenoxymethyl-4-oxa-2,6-diaza-bicyclo[3.2.0]hept-2-en-7-one