(2S,3R)-2-(3-Hydroxy-propyl)-5-methyl-3-((S)-1-methylcarbamoyl-5-trifluoromethanesulfonylamino-pentylcarbamoyl)-hexanoic acid tert-butyl ester

(2S,3R)-2-(3-Hydroxy-propyl)-5-methyl-3-[(S)-1-methylcarbamoyl-5-(4-nitro-benzenesulfonylamino)-pentylcarbamoyl]-hexanoic acid tert-butyl ester

(6S,9R,10S)-9-Isobutyl-6-methylcarbamoyl-8,13-dioxo-1,7-diaza-cyclotridecane-10-carboxylic acid

(6S,7R,10S)-7-Isobutyl-8-oxo-2-oxa-9-aza-bicyclo[10.2.2]hexadeca-1(15),12(16),13-triene-6,10-dicarboxylic acid 10-methyl ester

6-tert-butyl 10-methyl (6S,7R,10S)-7-isobutyl-8-oxo-2-oxa-9-azabicyclo[10.2.2]hexadeca-1(14),12,15-triene-6,10-dicarboxylate