{(R)-1-[(1S,2S,4R)-4-((S)-1-Benzylcarbamoyl-2-methyl-propylcarbamoyl)-2-hydroxy-1-isobutyl-pentylcarbamoyl]-2-methylsulfanyl-ethyl}-carbamic acid tert-butyl ester

(2R,4S,5S)-5-tert-Butoxycarbonylamino-4-hydroxy-2,7-dimethyl-octanoic acid

(2R,4S,5S)-5-[(tert-butoxycarbonyl)amino]-4-[(tert-butyldimethylsilyl)oxy]-2,7-dimethyloctanoic acid

tert-butyl (1S,2S,4R)-5-({(1S)-1-[(benzylamino)carbonyl]-2-methylpropyl}amino)-2-hydroxy-1-isobutyl-4-methyl-5-oxopentylcarbamate