Microwave-Induced Synthesis and Regio- and Stereoselective Epoxidation of 3-Styrylchromones
作者:Tamás Patonay、Attila Kiss-Szikszai、Vera M. L. Silva、Artur M. S. Silva、Diana C. G. A. Pinto、José A. S. Cavaleiro、József Jekő
DOI:10.1002/ejoc.200701081
日期:2008.4
highly regioselective epoxidation of (E)- and (Z)-3-styrylchromones have been elaborated. Treatment of the alkenes with dimethyldioxirane led to the exclusive formation of 3-(3-aryloxiran-2-yl)chromones with complete diastereoselectivity, whereas treatment with hydrogen peroxide under alkaline conditions afforded the corresponding 2,3-epoxy-3-styrylchromanones as the only products. Epoxidation performed
3-甲酰基色酮和苯丙二酸在醋酸钠载体上微波辅助无溶剂合成(E)-3-苯乙烯基色酮;该方法以中等至良好的收率和完全的非对映选择性提供苯乙烯基衍生物。(E)- 和 (Z)-3-styrylchromones 的高度区域选择性环氧化的协议已经详细说明。用二甲基二环氧乙烷处理烯烃导致形成具有完全非对映选择性的 3-(3-芳基环氧乙烷-2-基)色酮,而在碱性条件下用过氧化氢处理得到相应的 2,3-环氧-3-苯乙烯色酮作为只有产品。在手性非外消旋金鸡纳生物碱季铵盐存在下进行环氧化,合成富含对映体的 2,3-epoxy-3-styrylchromanones,但只有中等 ee 值。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)