An improved synthesis of pyridoxine (vitamin B6) is reported. The key step involves the light-promoted [2+2+2] cyclization of 3,3-bissilyl-di-2-propynyl ethers and acetonitrile in the presence of [cpCo(cod)] (1 mol%) as a catalyst. Convenient oxidation and iodination procedures are elaborated to transfer 3-silylpyridines into corresponding 3-hydroxy- and 3-iodo-derivatives.
报道了一种改进的
吡哆醇(
维生素B6)合成方法。关键步骤涉及在[cpCo(cod)](1摩尔%)催化剂存在下,3,3-双
硅烷基-二-2-
丙炔基醚和
乙腈的光催化[2+2+2]环化反应。详细阐述了将3-
硅烷基
吡啶转化为相应的3-羟基和3-
碘代衍
生物的便捷氧化和
碘化方法。