The tetrahydropyridine and piperidine subunits are widely found in biologically active molecules and natural products. Alhough considerable synthetic efforts have been made to reach these systems, there are few direct methods available for the preparation of enantionenriched tetrahydropyridines. A Lewis acid-promoted intramolecular imine crotylation is described and results in direct access to enantioenriched
四氢
吡啶和
哌啶亚基广泛存在于
生物活性分子和
天然产物中。尽管为达到这些系统已经进行了大量的合成努力,但很少有直接方法可用于制备富含对映体的四氢
吡啶。描述了
路易斯酸促进的分子内
亚胺巴豆化,并导致直接获得具有高非对映选择性的对映体富集的 2,6-顺-和 2,6-反-3-反-三取代四氢
吡啶。在 (-)-quinolizidine 217A 的权宜全合成中证明了该方法的应用示例。这种
天然产物的绝对立体
化学是通过全合成建立的。