{(S)-2-[(S)-2-[(S)-2-((2S,3S)-2-tert-Butoxycarbonylamino-3-methyl-pentanoylamino)-3-methyl-butyrylamino]-6-(2-chloro-benzyloxycarbonylamino)-hexanoylamino]-propionylamino}-acetic acid   、                                                                                      (S)-4-((S)-2-Methyl-1-{(S)-3-methyl-1-[(2-oxo-2-phenyl-ethoxycarbonylmethyl)-carbamoyl]-butylcarbamoyl}-propylcarbamoyl)-4-((2S,3S)-3-methyl-2-{(S)-2-[((S)-pyrrolidine-2-carbonyl)-amino]-propionylamino}-pentanoylamino)-butyric acid benzyl ester                                                                                                                                                              在
                                                                                                                                                                                 
1-羟基苯并三唑   、                                                                                                  
1-(3-二甲基氨基丙基)-3-乙基碳二亚胺                                                                                                                                  作用下,
                                                                                                                                                                                                                            以88%的产率得到Boc-Ile-Val-Lys(ClZ)-Ala-Gly-Pro-Ala-Ile-Glu(OBzl)-Val-Leu-Gly-OPac