(2S,3S)-2-{[(benzyloxy)carbonyl]amino}-5-hydroxy-3-methylpentanoic acid methyl ester

(S)-2-[(S)-2-(9H-Fluoren-9-ylmethoxycarbonylamino)-thiopropionylamino]-3-hydroxy-2-methyl-propionic acid allyl ester

(2S,3S)-2-[N-(tert-butoxycarbonyl)-N-methylamino]-3-methyl-5-[(triisopropylsilanyl)oxy]pentanoic acid methyl ester

(S)-2-({(S)-2-[(tert-butoxycarbonyl)amino]thiopropionyl}amino)-3-hydroxy-2-methylpropionic acid allyl ester

{(1S,2S)-2-methyl-1-[(R)-(1-phenylethyl)carbamoyl]but-3-enyl}carbamic acid benzyl ester