1,2,3,6-Tetrahydropyridines by Cycloaddition of 1-Alkoxy-1,3-dienes and (Tosyloxyimino)malononitrile

Article abstract of DOI:10.1055/s-1988-27663

1-Alkoxy-1,3-alkadienes and 5-vinyl-3,4-dihydro-2H-pyran (prepared by Wittig carbonyl olefination of 3-alkoxyacroleins and 5-formyl-3,4-dihydro-2H-pyran) undergo <4+2> cycloaddition with (tosyloxyimino)malononitrile in tetrahydrofuran/water at room temperature to give 5-alkyl-2,2-dicyano-6-ethoxy-1-tosyloxy-1,2,3,6-tetrahydropyridines and 7,7-dicyano-8-tosyloxy-3,4,6,7,8,8a-hexahydro-2H-pyrano<2,3-b>pyridine.These compounds can be converted into 6-alkoxy-5-alkyl-2,2-dicyano-2,3-dihydropyridines and pyridine-2-carboxamides, respectively.