Thio-claisen rearrangement approach to the synthesis of 2,3-disubstituted 4-piperidones
作者:Françoise Tubéry、David S. Grierson、Henri-Philippe Husson
DOI:10.1016/s0040-4039(00)96888-6
日期:1987.1
compounds whereas in the presence of added propionic anhydride the thio-ester was obtained. Under these latter conditions (R = C5H11CH(OSiX)CC-) rearranged to give a mixture of and whereas in DME containing CH3COOH-H2O (trace) the desired 2,3-disubstituted 4-piperidones and were obtained in 95 % combined yield.
由(Lawesson试剂,85%)制备的硫代哌啶酮与烯丙基溴进行快速反应,得到5,6-二氢吡啶鎓盐。通过与适当的格氏试剂反应,得到C-2官能化的中间体。在DME中于120℃加热(R = Pr)导致形成环化化合物,而在添加丙酸酐的存在下获得硫代酯。在这些后者的条件下(R = C 5 H ^ 11 CH(OSIX)CC-)重排,得到的混合物,并在DME含有CH而3 COOH-H 2O(痕量)所需的2,3-二取代的4-哌啶酮,以95%的合并产率获得。