(3S)-3-((2S)-2-[((2S)-2-[(2S)-2-(Acetylamino)-3-carboxypropanoyl]amino-4-carboxybutanoyl)amino]-3-methylbutanoylamino)-4-oxo-7-phenylheptanoic acid
3-{2-[2-(2-acetylamino-3-tert-butoxycarbonyl-propionylamino)-4-tert-butoxycarbonyl-butyrylamino]-3-methyl-butyrylamino}-6-(2,5-dimethyl-phenyl)-4-oxo-hexanoic acid tert-butyl ester
3-{2-[2-(2-acetylamino-3-tert-butoxycarbonyl-propionylamino)-4-tert-butoxycarbonyl-butyrylamino]-3-methyl-butyrylamino}-4-oxo-6-m-tolyl-hexanoic acid tert-butyl ester
(S)-3-{(S)-2-[(S)-2-((S)-2-Acetylamino-3-tert-butoxycarbonyl-propionylamino)-4-tert-butoxycarbonyl-butyrylamino]-3-methyl-butyrylamino}-4-oxo-7-phenyl-heptanoic acid methyl ester
(S)-3-{(S)-2-[(S)-2-((S)-2-Acetylamino-3-tert-butoxycarbonyl-propionylamino)-4-tert-butoxycarbonyl-butyrylamino]-3-methyl-butyrylamino}-4-cyclohexyl-4-oxo-butyric acid methyl ester