β-紫罗兰酮的合成工艺研究

Synthesis of β-Ionone

从山苍子油出发 ,经缩合、环化两步反应 ,直接合成 β 紫罗兰酮。研究了催化剂、溶剂的种类和用量、反应物配比、反应温度等因素对体系的影响。最佳合成工艺条件为 :缩合反应 :C -1作助催化剂 ,n(丙酮 )∶n(柠檬醛 ) =9∶1,n(主催化剂 )∶n(柠檬醛 ) =0 5 0∶1 0 0 ,主催化剂(NaOH水溶液 )质量分数 5 % ,反应温度 35℃ ,缩合转化率可达 98 4 % ;环化反应 :以氯仿作溶剂 ,H - 1作催化剂 ,m(催化剂 )∶m(假性紫罗兰酮 ) =2 0∶1 0 ,m(氯仿 )∶m(假性紫罗兰酮 ) =2 0∶1 0 ,反应温度 - 10℃ ,环化转化率可达 99 7%。产品总收率达 4 7 5 % ,w(β 紫罗兰酮 )≥92 %。

β-Ionone was obtained from Litsea cubeba oil through two step reaction of condensation and cyclization.Factors influencing the reaction were studied,such as kind and consumption of catalysts and solvents,ratio of reagents and reaction temperature.The optimum results showed that the rate of condensation achieved 98 4% at n (acetone)∶ n (citral) = 9∶1, n (major catalyst)∶ n (citral)=0 50∶1 00,concentration of major catalyst 5%,reation temperature 308 K and with C-1 as cocatalyst.The rate of cyclization achieved 99 7% at m (catalyst)∶ m (pseudoionone)=2 0∶1 0, m (solvent)∶ m (pseudoionone)=2 0∶1,reation temperature 263 K,with H-1 as catalyst and S-1 as solvent.The total yield was up to 47 5% with the product purity≥92%.