6-(Acetyl-benzyloxy-amino)-2-[(S)-2-(2-benzyloxy-benzoylamino)-3-hydroxy-propionylamino]-hexanoic acid methyl ester

6-(Acetyl-benzyloxy-amino)-2-{[(R)-2-(2-benzyloxy-phenyl)-4,5-dihydro-oxazole-4-carbonyl]-amino}-hexanoic acid

6-(Acetyl-benzyloxy-amino)-2-{[(R)-2-(2-benzyloxy-phenyl)-4,5-dihydro-oxazole-4-carbonyl]-amino}-hexanoic acid methyl ester

N2,N2-(1,5-citryl)bis

N2,N2-(anhydromethylene-1,5-citryl)bis