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(1992)4-nitrobenzyl (2'S,6R,7R)-3-acetoxymethyl-7-hydroxy(phenyl)acetylaminoceph-3-em-4-carboxylate
4-nitrobenzyl (5'S,6R,7S)-3-acetoxymethyl-4'-oxo-5'-phenylspiro(1',3'-oxazolidine-2',7-ceph-3-em)-4-carboxylate
4-nitrobenzyl (3S,5'S,5R,6S)-4'-oxo-5'-phenylspiro(1',3'-oxazolidine-2',6-penicillanate)
4-nitrobenzyl (2'S,3S,5R,6R)-6-hydroxy(phenyl)acetylaminopenicillanate
(5'S,6R,7S)-3-acetoxymethyl-4'-oxo-5'-phenylspiro(1',3'-oxazolidine 2',7-ceph-3-em)-4-carboxylic acid