固载杂多酸催化合成2-甲基-2-(4-甲基-3-戊烯基)-1,3-二氧六环

以离子交换树脂固载磷钨酸为催化剂合成了 2 -甲基 - 2 - (4-甲基 - 3 -戊烯基 ) - 1 ,3 -二氧六环。考察了影响收率的因素。其最优条件为 :6 -甲基 - 5 -庚烯 - 2 -酮∶ 1 ,3 -丙二醇∶催化剂∶带水剂为 1mol∶ 1 .5 mol∶ 1 2 g∶ 2 0 0 m L,反应在回流温度下进行 ,反应时间 3 .0 h。收率可达 89.6 %,催化剂可重复使用。

Synthesis of 2-Methyl-2-(4-methyl-3-pentenyl)-1,3-dioxane on Supported Heteropoly Acid Catalyst

Methyl-2-(4-methyl-3-pentenyl)-1,3-dioxane was synthesized using phosphotungstic acid supported on cationic exchange resin as catalyst. The factors affecting the condensation yield were investigated. The results showed that the optimum conditions are as follows:6-methyl-5-heptene-2-one∶1,3-propandiol∶catalyst∶dehydrating agent,1 mol∶1.5 mol∶12 g∶200 mL; reaction temperature, reflux temperature; reaction time, 3.0 h. The yield is above 89.6% under the optimum conditions. The Catalyst can be used repeatedly.