nonracemic Betti base as a chiral auxiliary. The key step is that the auxiliary residue was removed by a novel base-catalyzed N-debenzylation via a formation of o-quinone methide mechanism in stead of the traditional hydrogenolysis, by which the alkene or alkyne groups survived. By this method, ten 2-alkene- or 2-alkyne-containing chain substituted piperidines were prepared on the gram scale within
通过使用非外消旋的Betti碱作为手性助剂,建立了制备对映体纯的含2个烯烃或2个
炔烃的链取代
哌啶的一般方法。关键步骤是代替传统的氢解反应,通过传统的氢解反应,通过
邻甲基苯甲酸甲酯的形成,通过新颖的碱催化的N-脱苄基反应去除了辅助残基。通过这种方法,在数小时内以克为单位制备了十个含2-烯烃或2-
炔烃的链取代的
哌啶。为了证明该方法的有效性和产品的多功能性,使用(S)-2-烯丙基完成了天然
生物碱(+)-peltierine,(-)-lasubine II和(+)-cermizine C的总合成--N -Boc-
哌啶为通用成分。