(4-Nitrophenyl)methyl (5R-(5alpha,6alpha(R*)))-6-(1-hydroxyethyl)-3-((2-((((4-nitrophenyl)methoxy)carbonyl)amino)ethyl)thio)-7-oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylate 64067-13-6 EINECS 264-650-9