(S)-2-Allyloxycarbonylamino-4-((S)-3-allyloxycarbonylamino-3-carboxy-propyldisulfanyl)-butyric acid

(S)-4-[(S)-3-tert-Butoxycarbonyl-3-(4-methylamino-benzoylamino)-propyldisulfanyl]-2-(4-methylamino-benzoylamino)-butyric acid tert-butyl ester

(S)-2-Amino-4-((S)-3-amino-3-tert-butoxycarbonyl-propyldisulfanyl)-butyric acid tert-butyl ester