Preparation of (E)-4-Aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-ones as Fluorinated Building Blocks and Their Application in Ready and Highly Stereoselective Routes to trans-2,3-Dihydrofurans Substituted with Trifluoromethyl and Sulfonyl Groups
作者:Haigang Yu、Jing Han、Jie Chen、Hongmei Deng、Min Shao、Hui Zhang、Weiguo Cao
DOI:10.1002/ejoc.201200180
日期:2012.6
(E)-4-Aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-one fluorinated building blocks were prepared through a two-step process. Treatment of these (E)-4-aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-ones with arsonium bromides in the presence of Cs2CO3 in CH2Cl2 at reflux resulted in highly stereoselective ring closure to provide 4-tosyl-5-trifluoromethyl-trans-2,3-dihydrofurans in good to excellent yields.
(E)-4-Aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-one 氟化结构单元通过两步法制备。这些 (E)-4-芳基-1,1,1-trifluoro-3-tosylbut-3-en-2-ones 在 Cs2CO3 的 CH2Cl2 存在下用溴化砷处理回流导致高度立体选择性闭环,以提供4-tosyl-5-trifluoromethyl-trans-2,3-dihydrofurans 的产率很好。