for the following products
(2S,cis)-1-Pyrrolidinecarboxylic acid 2-[(dimethylamino)carbonyl]-4-mercapto-(4-nitrophenyl)methyl ester | 2-Dimethylcarbamoyl-4-mercapto-pyrrolidine-1-carboxylic acid 4-nitro-benzyl ester | Meropenem side chain | Side chain for meropenem and (2S,4S)-2-(Dimethylaminocarboxyl)-4-mercapto-1-(p-nitrobenzyloxycarbonyl)-1-pyrrolidine
