((S)-1-[(R)-1-[(6-amino-pyridin-3-ylmethyl)-carbamoyl]-2,2-dicyclohexyl-ethylcarbamoyl]-2-methylbutyl)carbamic acid tert-butyl ester   、                                                                                      
三氟乙酸                                                                                                                                                                                                                                                                      反应 1.0h,
                                                                                                                以19%的产率得到(S)-2-amino-3-methyl-pentanoic acid {(R)-1-[(6-amino-pyridin-3-ylmethyl)-carbamoyl]-2,2-dicyclohexyl-ethyl}amide ditrifluoroacetate