Imipenem, protected

protected imipenem ; (4r,5s,6s)-4-nitrobenzyl-3-[[(3s,5s)-5-[(dimethylamino)carbonyl]-1-[[(4-nitrobenzyl)oxy] carbonyl]-3-pyrrolidinyl]thio]-6-[(1r)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3,2,0] hept-2-ene-2-carboxylate ; [5r-α,6α(r*)]]- 6-(1-hydroxyethyl)-3-[[2-[[[[[(4-nitrophenyl)methoxy]carbonyl]amino]methylene]amino] ; bis protected imipenem ; (5r,6s)-4-nitrobenzyl-3-[[2-[[[[[(4-nitrophenyl)methoxy]carbonyl]amino]methylene]amino]ethyl]thio]-6-[(1r)-1-hydroxyethyl]-7-oxo-1-azabicyclo[3,2,0]hept-2-ene-2-carboxylate