Although the reaction mechanism is obscure at present, 2,4,4,6-tetrabromo-2,5-cyclohexadien-1-one (2) was found to be a good reagent for the selective bromination of polyenes, that is, terminal double bond of geranyl and farnesyl cyanides was selectively brominated by merely being stirred with equimolar amount of 2 in CH2Cl2 solution, giving 6,7-dibromogeranyl (yield 98%) and 10,11-dibromofarnesyl (yield 65%) cyanide, respectively.
虽然反应机理目前尚不清楚,但我们发现 2,4,4,6-四
溴-2,5-环
己二烯-1-酮(2)是一种选择性
溴化多烯的良好试剂,即只需在
CH2Cl2 溶液中加入等摩尔量的 2,就能选择性地
溴化香叶基和法呢基
氰化物的末端双键、只需在 溶液中加入等摩尔量的 2,即可选择性地
溴化香叶基和法呢基
氰化物的末端双键,分别得到 6,7 二
溴香叶基(收率 98%)和 10,11 二
溴法呢(收率 65%)
氰化物。