benzyl 4-[(5S)-5-butyl-2-oxo-1-oxa-3,9-diazaspiro[5.5]undecan-9-yl]-4-methylpiperidine-1-carboxylate   、                                                                                      
1-Boc-4-溴甲基哌啶                                                                                                                                                              在
                                                                                                                                         
四丁基溴化铵                                                                                                                                                                                                                               sodium hydroxide                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                    反应 72.0h,
                                                                                                                以82%的产率得到benzyl (S)-4-(3-((1-(tert-butoxycarbonyl)piperidin-4-yl)methyl)-5-butyl-2-oxo-1-oxa-3,9-diazaspiro[5.5]undecan-9-yl)-4-methylpiperidine-1-carboxylate