Lewis Acid-Mediated Reactions of 1-Cyclopropyl-2-arylethanone Derivatives with Allenic Ester, Ethyl Acetoacetate, and Methyl Acrylate
作者:Min Shi、Xiang-Ying Tang、Yong-Hua Yang
DOI:10.1021/jo800608h
日期:2008.7.1
TMSOTf-mediated reactions of 2-aryl-1-(1-phenylcyclopropyl)ethanones 1 with allenic esters afford a novel method for the synthesis of 6-methyl-3a,7-diaryl-3,3a-dihydro-2H-benzofuran-4-one derivatives 2 in moderate yields. In addition, we also found that TMSOTf-mediated reactions of 1-cyclopropyl-2-arylethanones with ethyl acetoacetate can provide the corresponding 2,3-dihydrobenzofuran-4-ol and dihydrofuro[2
TMSOTf介导的2-芳基-1-(1-苯基环丙基)乙炔酮1与烯丙酸酯的反应为合成6-甲基-3a,7-二芳基-3,3a-二氢-2 H-苯并呋喃-提供了一种新方法4-一衍生物2的产率中等。此外,我们还发现,TMSOTf介导的1-环丙基-2-芳基蒽酮与乙酰乙酸乙酯的反应可提供相应的2,3-二氢苯并呋喃-4-醇和二氢呋喃[2,3 - h ]铬-2-酮通过涉及H 2的环丙烷的亲核开环反应的顺序反应获得中等收率O,一个分子间的醇醛型反应和两个分子内的醇醛型反应,循环酯交换,脱水和芳构化。而且,通过使用丙烯酸甲酯代替烯丙酸酯,相应的7-芳基-3,5,6,7-四氢-2 H-苯并呋喃-4-酮和5-芳基-3,5,6,7-四氢-在Bi(OTf)2 Cl存在下,可以中等至高产率形成2 H-苯并呋喃-4-酮。在控制实验的基础上,还提供了合理的反应机理。