2-<3-benzyl-6-oxo-2-thia-4,7-diaza-(1R,5R)-bicyclo-<3.2.0>-hept-3-en-7-yl>-β-(trimethylsilyl)-ethyl acetate

2-((1R,5R)-3-Benzyl-7-oxo-4-thia-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl)-3-methyl-but-2-enoic acid benzyl ester