4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,6-[[(2S)-2-(acetylamino)-6-[[[(4-nitrophenyl)methoxy]carbonyl]amino]-1-oxohexyl]amino]-3,3-dimethyl-7-oxo-, (4-nitrophenyl)methyl ester,(2S,5R,6R)- [ 919768-53-9 ]