(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