(R)-2-((1R)-7-oxo-3-phenyl-(1rH,5cH)-4-oxa-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl)-3-phenylsulfanylmethyl-but-3-enoic acid benzhydryl ester

(R)-3-nitrooxymethyl-2-((1R)-7-oxo-3-phenyl-(1rH,5cH)-4-oxa-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl)-but-3-enoic acid benzhydryl ester