(3S,4S)-3-((tert-butyldimethylsilyl)oxy)-4-methyloctanoic acid

(3S,4S)-3-((R)-2-tert-Butoxycarbonylamino-4-methyl-pentanoyloxy)-4-methyl-octanoic acid 4-nitro-benzyl ester

(3S,4S)-3-{(R)-2-[(S)-2-((S)-2-Amino-3-phenyl-propionylamino)-propionylamino]-4-methyl-pentanoyloxy}-4-methyl-octanoic acid

(R)-2-((S)-2-{(S)-2-[(3S,4S)-3-(tert-Butyl-dimethyl-silanyloxy)-4-methyl-octanoylamino]-3-phenyl-propionylamino}-propionylamino)-4-methyl-pentanoic acid

(R)-2-((S)-2-{(S)-2-[(3S,4S)-3-(tert-Butyl-dimethyl-silanyloxy)-4-methyl-octanoylamino]-3-phenyl-propionylamino}-propionylamino)-4-methyl-pentanoic acid benzyl ester