Novel and facile synthesis of β-(4-azuleno[1,2-b]thienyl)- and β-(4-azuleno[2,1-b]thienyl)-α,β-unsaturated ketones by intramolecular tropylium ion-mediated furan ring-opening reaction
作者:Kimiaki Yamamura、Naoki Kusuhara、Akihiro Kondou、Masao Hashimoto
DOI:10.1016/s0040-4020(02)00869-4
日期:2002.9
The novel and efficient methods for the synthesis of β-(4-azuleno[1,2-b]thienyl)-α,β-unsaturated ketones (1) and β-(4-azuleno[2,1-b]thienyl)-α,β-unsaturated ketones (2) have been described. Refluxing the dichloromethane solutions of 2-tropylio-3-(2-furyl)thiophene tetrafluoroborates (3) or 3-tropylio-2-(2-furyl)thiophene tetrafluoroborates (4) afforded (1) and (2), respectively, in moderate yields
合成β-(4-azuleno [1,2- b ]噻吩基)-α,β-不饱和酮(1)和β-(4-azuleno [2,1- b ]噻吩基)的新颖有效方法已经描述了-α,β-不饱和酮(2)。回流2-对甲苯基-3-(2-呋喃基)噻吩四氟硼酸酯(3)或3-对甲苯基-2-(2-呋喃基)噻吩四氟硼酸酯(4)的二氯甲烷溶液,分别得到(1)和(2)。中等产量。该反应涉及分子内的yl离子介导的呋喃开环反应。