7-[(R)-3-((S)-1-tert-Butoxycarbonylamino-ethyl)-pyrrolidin-1-yl]-8-chloro-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid

7-[(S)-3-((R)-1-tert-Butoxycarbonylamino-ethyl)-pyrrolidin-1-yl]-1-ethyl-6,8-difluoro-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid

1-benzyl-4-(1-hydroxyiminoethyl)-2-pyrrolidone

(S)-9-[(R)-3-((S)-1-tert-Butoxycarbonylamino-ethyl)-pyrrolidin-1-yl]-8-fluoro-3-methyl-6-oxo-2,3-dihydro-6H-1-oxa-3a-aza-phenalene-5-carboxylic acid