Synonyms: 1-Azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid, 3-[(diphenoxyphosphinyl)oxy]-6-(1-hydroxyethyl)-4-methyl-7-oxo-,(4-nitrophenyl)methyl ester, [4R-[4a,5b,6b(R*)]]-;4-Nitrobenzyl(4R,5S,6S)-3-[(diphenylphosphono)oxy]-6-[(R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate;p-Nitrobenzyl(4R,5R,6S)-3-diphenylphosphoryloxy-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate;beta-Methyl vinyl phosphate (MAP);(4R,5R,6S)-4-nitrobenzyl 3-(diphenoxy phosphoryloxy)-6-((R)-1-hydroxyethyl)-4-methyl-7-oxo-1-azabicyclo[3.2.0] hept-2-ene-2-carboxylate; MAP;1-Azabicyclo[3.2.0]hept-2-ene-2-carboxylicacid, 3-[(diphenoxyphosphinyl)oxy]-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-,(4-nitrophenyl)methyl ester, (4R,5R,6S)-;