[(1S,2S)-1-Benzyl-3-((R)-4-tert-butylcarbamoyl-thiazolidin-3-yl)-2-hydroxy-3-oxo-propyl]-carbamic acid benzyl ester

(R)-N-tert-butyl-3-[(2S,3S)-3-[(S)-2-(tert-butoxycarbonyl)amino-3-methylbutanoyl]amino-2-hydroxy-4-phenylbutanoyl]-1,3-thiazolidine-4-carboxamide

(R)-N-tert-butyl-3-[(2S,3S)-3-[(S)-2-(tert-butoxycarbonyl)aminopentanoyl]amino-2-hydroxy-4-phenylbutanoyl]-1,3-thiazolidine-4-carboxamide

(R)-N-tert-butyl-3-[(2S,3S)-3-[(S)-2-(tert-butoxycarbonyl)amino-3,3-dimethylbutanoyl]amino-2-hydroxy-4-phenylbutanoyl]-1,3-thiazolidine-4-carboxamide

(R)-N-tert-butyl-3-[(2S,3S)-3-[(S)-2-(tert-butoxycarbonyl)aminosuccinamyl]amino-2-hydroxy-4-phenylbutanoyl]-1,3-thiazolidine-4-carboxamide