研究了以固载强酸TiO2 SO4 2 -作催化剂 ,用假性异甲基紫罗兰酮环化合成甲基紫罗兰酮的新方法。提高了α 异甲基紫罗兰酮的收率 ,获得了最佳反应条件 :投料比n(假性异甲基紫罗兰酮 )∶n(甲苯 )∶n(硫酸 ) =1∶3.5∶0 .0 4 ,控制反应温度 1 5～ 2 5℃ ,反应时间 1 .5h。该优化条件下 ,合成收率为93%～ 94 % ,产物中α 异甲基紫罗兰酮占 78(wt) %左右 A new method for the cyclization of methyl ionone with pseudoisomethylionone using a strong acid TiO2 SO4 2 as a catalyst was studied. The yield of α-isomethylionone was increased and the optimum reaction conditions were obtained: the ratio of n (pseudoisomethyl ionone): n (toluene) :n (sulfuric acid) = 1: 3.5: , Controlling the reaction temperature 15 ~ 25 ℃, the reaction time 1.5 h. Under this optimized condition, the yield of synthesis was 93% ~ 94%, α-isomethylionone in the product accounted for 78% by weight