(S)-benzyl 3-(((S)-1-(tert-butoxy)-1-oxopropan-2-yl)amino)pyrrolidine-1-carboxylate

(S)-tert-butyl 2-((S)-pyrrolidin-3-ylamino)propanoate hydrochloride

(3'S,5S)-1'-((S)-2-isobutyl-5-oxo-2,5-dihydro-1H-pyrrol-3-yl)-5-methyl-[1,3'-bipyrrolidine]-2,4-dione

(S)-4-(tert-butoxy)-5-((S)-sec-butyl)-1-((S)-1-((S)-1-((S)-1-((S)-2-isobutyl-5-oxo-2,5-dihydro-1H-pyrrol-3-yl)pyrrolidin-3-yl)-2-methyl-5-oxo-2,5-dihydro-1H-pyrrol-3-yl)pyrrolidin-3-yl)-1H-pyrrol-2(5H)-one