N-(2-propenyl)-N-[[[[N'-(2-propenyl)-N'-(1S)-1-methoxycarbonyl-3-methyl-butyl]carbonyl]-N''-(benzyl)-amino]sulfonyl]-(S)-leucine methyl ester

Boc-(Nall)Leu-OH

Boc-(Nall)Leu-(Nall)Gly-OEt

tert-butyl (S)-4-((S)-1-methoxy-4-methyl-1-oxopentan-2-yl)-2-methyl-3-oxopiperazine-1-carboxylate

(2S,3'S)-2-isobutyl-2-[4'-(tert-butoxycarbonyl)-3'-methyl-2'-oxopiperazin-1'-yl]acetic acid