Substituent Effects in the Diels-Alder Reaction of Substituted Benzynes with Hexamethylcyclohexa-2,4-dienone
作者:Akira Oku、Akira Matsui
DOI:10.1246/bcsj.50.3338
日期:1977.12
10-hexamethyl-1,4-dihydro-1,4-. ethanonaphthalene-9-one (Type 7) and its 8- or 7-substituted isomer (Type 8). The 7/8 isomer ratios varied from 1.0 to 2.0 depending substantially on the size and the position of substituents of the benzynes and also on the temperature and the solvent. The ratios were the same when two positionally isomeric acids, i.e., 3- and 6-, or 4- and 5-substituted acids, were used as the
由 3-Me-、4-Me-、5-Me-、6-Me-、3,4-Me2-、3-NO2-、4-NO2- 生成的不对称取代苄的 Diels-Alder 反应, 5-NO2- 和 3-Cl-苯重氮-2-羧酸盐与六甲基环己-2,4-二烯酮得到 5- 或 6- 取代的 1,2,3,4,10,10- 的混合物六甲基-1,4-二氢-1,4-。ethanonaphthalene-9-one (Type 7) 及其 8- 或 7- 取代的异构体 (Type 8)。7/8 异构体比例在 1.0 到 2.0 之间变化,这主要取决于苄基取代基的大小和位置以及温度和溶剂。当两种位置异构的酸,即3-和6-,或4-和5-取代的酸用作前体时,比例是相同的。因此,证明了由这些配对的异构前体产生的苄的身份,排除前体固有记忆效应的可能性。控制异构体比例的因素是根据苄基和…的取代基之间的空间排斥相互作用来讨论的。