[2.5]octa-1,4,7-trien-6-one 4 changed to 2-aryl-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)benzofuran 5 in a more than 90% yield. The selective formation of 5 is ascribed to a neighbouring group participation of the ortho-methoxyl group to an incipient vinyl cation.
在
乙醇水溶液中 1-芳基-5,7-二叔丁基-2-(o-
甲氧基苯基)螺[2.5]octa-1,4,7-trien-6-one 4 变为 2-aryl-3- (3',5'-二叔丁基-4'-羟基苯基)
苯并呋喃 5 产率超过 90%。5 的选择性形成归因于邻甲氧基团的相邻基团与初始
乙烯基阳离子的参与。