(S)-2-[((2S,4R)-2-tert-Butoxycarbonylamino-4-methyl-octanoyl)-methyl-amino]-4-methyl-pentanoic acid methyl ester

(S)-2-{[(2S,4R)-2-((R)-2-tert-Butoxycarbonylamino-4-cyano-butyrylamino)-4-methyl-octanoyl]-methyl-amino}-4-methyl-pentanoic acid

(S)-2-{[(2S,4R)-2-((R)-2-tert-Butoxycarbonylamino-4-cyano-butyrylamino)-4-methyl-octanoyl]-methyl-amino}-4-methyl-pentanoic acid methyl ester