Abstract 2-Formyl-4,4-dimethylcyclohexa-2,5-dien-1- one undergoes hetero-Diels-Alder reactions with electron-rich olefins to yield 3-substituted-5,5-dimethyl-3,4,4a,5-tetrahydro-8H-2-benzopyrane-8-ones. The endo addition is favoured.
摘要 2-Formyl-4,4-二甲基环己-2,5-dien-1-one 与富电子烯烃发生杂狄尔斯-阿尔德反应生成 3-取代-5,5-二甲基-
3,4,4a, 5-四氢-8H-2-苯并
吡喃-8-酮。内添加是有利的。