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.
[EN] 1,3 DIHYDROFURO [3,4-c]PYRIDINES AND THEIR PREPARATION<br/>[FR] 1,3 DIHYDROFURO [3,4-C]PYRIDINES ET PROCEDE PERMETTANT DE LES PREPARER
申请人:DSM IP ASSETS BV
公开号:WO2005090356A1
公开(公告)日:2005-09-29
The present invention relates to novel 1,3-dihydrofuro[3,4-c]pyridines which are useful intermediates in the synthesis of pyridoxines and a method for their preparation by cobalt(I) complex-catalysed [2 + 2 + 2]-cycloaddition of di-[(3-dimethyl-C1-4-alkoxysilyl)2-propynyl)] ethers with acetonitrile.