(S)-1-((R)-2-{(S)-2-[(S)-5-Benzyloxycarbonylamino-2-((S)-2-tert-butoxycarbonylamino-3-methyl-butyrylamino)-pentanoylamino]-4-methyl-pentanoylamino}-3-phenyl-propionyl)-pyrrolidine-2-carboxylatetetrabutyl-ammonium; 、
H-Val-Orn(Z)-Leu-D-Phe-Pro-OEt*HCl 在
(5-nitropyridyl)diphenyl phosphinate 作用下,
以
N,N-二甲基甲酰胺 为溶剂,
以70%的产率得到Boc-Val-Orn(Z)-Leu-D-Phe-Pro-Val-Orn(Z)-Leu-D-Phe-Pro-OEt