(1-氮杂双环[2.2.2]-3-辛基)-(4-甲氧基苄基)-胺   、                                                                                      
(rac)-(4-isobutyl-5-oxo-2-phenyl-4,5-dihydro-oxazol-4-yl)-acetic acid tert.-butyl ester                                                                                                                                                                                              以
                                                                                         various solvent(s)                                                                                  为溶剂,
                                                                                                                                                                                        以32%的产率得到(R)-3-benzoylamino-3-<(S)-1-cyclohexylcarbamoyl-2-phenyl-ethylcarbamoyl>-5-methyl-hexanoic acid tert.-butyl ester