(S)-2-[(R)-2-(2-tert-Butoxycarbonylamino-acetylamino)-3-phenyl-propionylamino]-4-methylsulfanyl-butyric acid methyl ester

({(R)-1-[(S)-3-Methyl-1-(N'-phenyl-hydrazinocarbonyl)-butylcarbamoyl]-2-phenyl-ethylcarbamoyl}-methyl)-carbamic acid tert-butyl ester

Boc-Gly-DL-Phe(β-OH)-OH