Reductive rearrangement of 2-aroyl-2,3-dihydrobenzofurans into 2-hydroxydihydrochalcones and flav-2-enes
作者:Dmitry V. Osipov、Maxim R. Demidov、Vitaly А. Osyanin、Yuri N. Klimochkin
DOI:10.1007/s10593-021-03039-6
日期:2021.12
4-diaryl-substituted 4H-chromenes by the formal [4+1] cycloaddition reaction of o-quinone methides and pyridinium ylides followed by reductive rearrangement of 2-aroyl-2,3-dihydrobenzofurans by the action of zinc in acetic acid or samarium and trimethylchlorosilane in 1,4-dioxane. The reduction of 3-unsubstituted 2-aroyl-2,3-dihydrobenzofurans by the action of zinc in acetic acid leads mainly to 2-hydroxydihydrochalcones
提出了通过邻醌甲基化物和吡啶鎓叶立德的形式 [4+1] 环加成反应然后还原重排合成 2-芳基和 2,4-二芳基取代的 4 H-色烯的两步程序。 2-芳酰基-2,3-二氢苯并呋喃通过乙酸中的锌或钐和 1,4-二恶烷中的三甲基氯硅烷的作用。通过乙酸中锌的作用还原 3-未取代的 2-芳酰基-2,3-二氢苯并呋喃主要产生 2-羟基二氢查耳酮。