1,2,3,6 Tetrahydropyridine durch [4 + 2]-Cycloaddition von 1-Alkoxy-1,3-dienen und (Tosyloxyimino)malodinitril
作者:Walter Dormagen、Klaus Rotscheidt、Eberhard Breitmaier
DOI:10.1055/s-1988-27663
日期:——
1,2,3,6-Tetrahydropyridines by [4 + 2] Cycloaddition of 1-Alkoxy-1,3-dienes and (Tosyloxyimino)malononitrile 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.
1,2,3,6-四氢吡啶,通过 1-烷氧基-1,3-二烯和 (甲苯磺酰氧基亚氨基)丙二腈 1-烷氧基-1,3-链二烯和 5-乙烯基-3,4-二氢的 [4 + 2] 环加成反应生成-2H-吡喃(通过 3-烷氧基丙烯醛和 5-甲酰基-3, 4-二氢-2H-吡喃的 Wittig 羰基烯化制备)在四氢呋喃/水中于室温下与(甲苯磺酰氧基亚氨基)-丙二腈进行 [4 + 2] 环加成反应,得到得到 5-烷基-2, 2-二氰基-6-乙氧基-1-甲苯磺酰氧基-1,2,3,6-四氢吡啶和 7,7-二氰基-8-甲苯磺酰氧基-3, 4,6,7,8,8a -六氢-2H-吡喃并[2,3-b]吡啶。这些化合物可以分别转化为6-烷氧基-5-烷基-2,2-二氰基-2,3-二氢吡啶和吡啶-2-甲酰胺。