Intramolecular Diels-Alder reactions of 2(1H)-pyrazinones: Synthesis of new Furo/Pyrano-pyridinones and -pyridines
作者:Kris J. Buysens、Didier M. Vandenberghe、Suzanne M. Toppet、Georges J. Hoornaert
DOI:10.1016/0040-4020(95)00802-f
日期:1995.11
4-alkynyloxy side chain and 2(1H)-pyrazinones 9–10 carrying the corresponding 2- or 3-alkynyloxy(m)ethyl substituent are shown to undergo intramolecular Diels-Alder reaction. The formation of either fused pyridinones 13, 16, 20, 22 or 24 and/or pyridines 14, 17, 19 or 25 depends on the substitution pattern of the anchored pyrazinone and runs via the loss of either nitrile or isocyanate from the intermediate
2(1 H)-吡嗪酮2-5,在3-位带有3-或4-炔基氧基侧链,2(1 H)-吡嗪酮9-10带有相应的2-或3-炔基氧基(m)乙基取代基显示出发生分子内Diels-Alder反应。是稠合吡啶酮的形成13,16,20,22或24和/或吡啶14,17,19或25取决于锚定的吡嗪酮和运行的取代模式通过中间体环加合物损失了腈或异氰酸酯。还讨论了氧原子的位置和侧链的长度对反应条件的影响。