Synthetic and Theoretical Investigations on the Construction of Oxanorbornenes by a Michael Addition and Intramolecular Diels-Alder Furan Reaction
作者:Mamta Dadwal、Manoj K. Kesharwani、Vaishalee Danayak、Bishwajit Ganguly、Shaikh M. Mobin、Rajendran Muruganantham、Irishi N. N. Namboothiri
DOI:10.1002/ejoc.200800681
日期:2008.12
The conjugate addition of nucleophiles such as allylmercaptan, allyl- and homoallylmalonate and diallylamine to β-furyl enones and acrylate, provides the Michael adducts in good yield. A facile intramolecular Diels–Alder reaction between the unsaturated tether and the furan diene ensues when these adducts are heated in a solvent such as toluene orxylene to afford the cycloadducts in good yield and
亲核试剂如烯丙基硫醇、烯丙基-和高烯丙基丙二酸酯和二烯丙胺与β-呋喃烯酮和丙烯酸酯的共轭加成以良好的产率提供迈克尔加合物。当这些加合物在甲苯或二甲苯等溶剂中加热时,不饱和系链和呋喃二烯之间会发生轻松的分子内 Diels-Alder 反应,在大多数情况下以良好的收率和优异的立体选择性提供环加合物。这些环加合物的结构和立体化学通过广泛的 NMR 实验和 X 射线晶体学得到证实。过渡态和产物几何结构的量子化学计算表明,环加合物的形成,其中新形成的环与氧降冰片烯骨架外稠合,