三酸复合体系催化α-蒎烯合成松油醇研究

Synthesis of Terpineol fromα-Pinene Catalyzed by Triple Acid Composite System

以柠檬酸为代表的α-羟基羧酸与磷酸和以丙酸为代表的低碳链脂肪酸组成三酸复合催化体系,应用于α-蒎烯的催化水合制备松油醇。考察了溶剂种类、脂肪酸链长、α-羟基酸种类、催化剂用量、水用量、反应温度和反应时间对水合反应的影响。结果表明:在α-蒎烯、水、丙酸、柠檬酸、磷酸的质量比为1∶1∶2∶0.05∶0.1和反应温度70℃、反应时间24 h的反应条件下,α-蒎烯转化率、松油醇GC含量和选择性可分别达到99.0%、53.3%和54.9%。在同样条件下将α-蒎烯水合时产生的单环单萜烯类副产物加入起始原料一起反应,可以提高目标产物松油醇的选择性,当加入量为40%时,松油醇选择性可提高到76%。产物组成分析发现:产物中总松油醇GC含量为53.3%,总水合产物GC含量为57.1%,总丙酸酯GC含量为8.1%。

The triple acid catalyst system composed ofα-hydroxycarboxylic acid represented by citric acid,phosphoric acid and low carbon chain fatty acid represented by propionic acid was applied to the catalytic hydration ofα-pinene to synthesize terpineol.The effects of solvent type,fatty acid chain length,α-hydroxycarboxylic acid type,catalyst amount,water amount,reaction temperature and reaction time on the hydration reaction were investigated.The results showed that under the reaction conditions of the mass ratio ofα-pinene,water,propionic acid,citric acid and phosphoric acid of 1∶1∶2∶0.05∶0.1,reaction temperature of 70℃and reaction time of 24 h,the conversion ofα-pinene,the GC content of terpineol and the product selectivity could reach 99.0%,53.3%and 54.9%,respectively.Under the same conditions,the selectivity of the target product terpineol could be improved by adding the monocyclic monoterpene by-products generated during the hydration ofα-pinene to the starting material.When the addition amount was 40%,the selectivity of terpineol could be increased to 76%.The product composition analysis showed that the total GC content of terpineol in the product was 53.3%,the total GC content of hydrate was 57.1%,and the total content of propionate was 8.1%.