[(S)-1-((S)-3-Benzyl-1,4-dioxo-hexahydro-pyrrolo[1,2-a]pyrazine-2-carbonyl)-2-methyl-propyl]-carbamic acid benzyl ester

[(S)-2-((S)-3-Benzyl-1,4-dioxo-hexahydro-pyrrolo[1,2-a]pyrazin-2-yl)-1-hydroxymethyl-2-oxo-ethyl]-carbamic acid tert-butyl ester

methyl ((R)-2-((tert-butoxycarbonyl)amino)-3-((4-methoxybenzyl)selanyl)propanoyl)-L-prolyl-L-phenylalaninate

(S,S)-N-(4-dimethoxymethyl-benzoyl)proline-phenylalanine carboxylic acid hydrazide

(S,S)-N-(3-dimethoxymethyl-benzoyl)proline-phenylalanine carboxylic acid hydrazide