Synthesis of Thienobenzofuranquinone Derivatives by Photoinduced and CAN-mediated 3+2-Type Cycloaddition Reactions
作者:Kazuhiro Kobayashi、Keiichi Yoneda、Kazutaka Hayashi、Osamu Morikawa、Hisatoshi Konishi
DOI:10.3987/com-05-10359
日期:——
8-tetrahydrothieno[2,3-f]benzofuran-6-carboxylates (2). Cerium(IV) ammonium nitrate (CAN)-mediated cycloaddition of ethyl 5-hydroxy-4,7-dioxo-4,7-dihydrobenzo[b]thiophene-2-carboxylates (1) to alkenes or phenylacetylene, giving ethyl 4,8-dioxo-4,8-dihydrothieno[2,3-f]benzofuran-6-carboxylate (2 or 4) and ethyl 4,5-dioxo-4,5-dihydrothieno[3,2-g]benzofuran-7-carboxylate derivatives (3 or 5), is also reported.
5-hydroxy-3-methyl-4,7-dioxo-4,7-dihydrobenzo[b]thiophene-2-carboxylate (la) 和烯烃之间的光诱导环加成反应生成 7-methyl-4,8-dioxo 乙酯-2,3,4,8-四氢噻吩并[2,3-f]苯并呋喃-6-羧酸盐 (2)。铈 (IV) 硝酸铵 (CAN) 介导 5-羟基-4,7-二氧代-4,7-二氢苯并[b]噻吩-2-羧酸乙酯 (1) 与烯烃或苯乙炔的环加成反应,得到 4,8 乙酯-dioxo-4,8-dihydrothieno[2,3-f]benzofuran-6-carboxylate(2 或 4)和 4,5-dioxo-4,5-dihydrothieno[3,2-g]benzofuran-7-carboxylate还报告了衍生物(3 或 5)。