A new approach to fused furan ring systems and benzofurans: intramolecular cyclization reactions of unsaturated acyloxy sulfone derivatives
作者:Yuan Liu、Hollie K. Jacobs、Aravamudan S. Gopalan
DOI:10.1016/j.tetlet.2011.03.120
日期:2011.6
Unsaturated acyloxy sulfones 3 undergo intramolecular cyclization upon deprotonation with LHMDS in THF. Dehydration and double bond isomerization of the products upon exposure to acid, gave the fused ring furans, 4, in good yields. This strategy could be readily adapted to prepare substituted benzofurans 12 from the cyclization reactions of acyloxy sulfones 11 prepared from phenols. Finally, this approach
不饱和酰氧基砜3在 THF 中用 LHMDS 去质子化后发生分子内环化。产物在暴露于酸时脱水和双键异构化,以良好的产率得到稠环呋喃4。这种策略可以很容易地适用于由酚类制备的酰氧基砜11的环化反应制备取代的苯并呋喃12。最后,可以成功修改这种方法以获取二氢吡喃和苯并吡喃。