(S)-2-tert-Butoxycarbonylamino-5-ethoxycarbonyloxy-5-oxo-pentanoic acid benzyl ester

(S)-2-{[(S)-2-((S)-5-Benzyloxy-2-tert-butoxycarbonylamino-pentanoylamino)-3-phenyl-propionyl]-methyl-amino}-3-[4-(tert-butyl-dimethyl-silanyloxy)-phenyl]-propionic acid methyl ester