Nucleophilic additions to pyridinium salts. Reduction of the intermediate dihydropyridines
作者:Rodolfo Lavilla、Teresa Gotsens、Francisco Gullón、Joan Bosch
DOI:10.1016/s0040-4020(01)90433-8
日期:1994.4
Reduction of indolyldihydropyridines 4 and 5 satisfactorily gave the corresponding tetrahydropyridines 6 and 7. A similar reduction of 4-(2-indolylmethyl)-1,4-dihydropyridines 3 was inefficient. In contrast, dihydropyridine 19 was reduced to 23 and then cyclized to pentacycle 24. Direct cyclization of 19 resulted in the formation of imide 21.
吲哚基二氢吡啶4和5的还原令人满意地得到相应的四氢吡啶6和7。4-(2-吲哚基甲基)-1,4-二氢吡啶3的类似还原是无效的。相反,二氢吡啶19被还原为23,然后环化为五环24。19的直接环化导致酰亚胺21的形成。