Synthesis of 2,3‐Dihydro‐4<i>H</i>‐furo[3,2‐c] chromen‐4‐ones and 2,3‐Dihydronaphtho[2,3‐b]furan‐4,9‐diones by the Radical Cyclizations of Hydroxyenones with Electron-Rich Alkenes using Manganese(III) Acetate
作者:Mehmet Yılmaz、Mehtap Yakut、A. Tarık Pekel
DOI:10.1080/00397910701845456
日期:2008.2.1
Abstract We have obtained dihydrofurans 3a–j in the radical cyclization of 4‐hydroxycoumarin 1a and 2‐hydroxy‐1,4‐naphtoquinone 1b with electron rich alkenes 2a–i by manganese(III) acetate. Methods A and B, which have different molar ratios were studied comparatively in these reactions, and we observed that method B (molar ratio 2:1:3) gave the best results. Treatment of 4‐hydroxycoumarin 1a and electron
摘要 我们通过乙酸锰 (III) 对 4-羟基香豆素 1a 和 2-羟基-1,4-萘醌 1b 与富电子烯烃 2a-i 进行自由基环化反应获得了二氢呋喃 3a-j。在这些反应中对具有不同摩尔比的方法 A 和 B 进行了比较研究,我们观察到方法 B(摩尔比 2:1:3)给出了最好的结果。用方法 B 处理 4-羟基香豆素 1a 和富电子烯烃 2a-e 得到 2,3-二氢-4H-呋喃[3,2-c]色烯-4-酮 3a-e,产率为 36-86%。相同条件下,2-羟基-1,4-萘醌1b与共轭烯烃2b和2f-i反应得到2,3-二氢萘并[2,3-b]呋喃-4,9-二酮3f-j优良的产量。