Study Of The Synthesis And Purification Of γ-undecalactone

γ-undecalactone is a very important kind of lactone perfumes. It is also named peach aldehyde since it has a strong fragrance of peach with it. The preparation and purification technology ofγ-undecalactone which are researched in this paper are highly interested recently due to its extensive application in daily chemical essence and edible essence. This paper will provide industrial production with theoretical guidance.Via free radical addition reaction,γ-undecalactone's crude product was prepared from n-butanol and methacrylate in the presence of di-tert-butyl peroxide initiator. Under the monitoring of the reaction process with gas chromatography, the influencing factors of the free radical addition reaction were systematically investigated. The experimental results indicate that the best inventory ratio of n-butanol and methacrylate is 1:7; catalyst amount is 1%( based on total mass of material); reaction time is 8h; reaction tempreture is 180℃; feeding time of constant pressure funnel is 2.5h; the yield based on methacrylate reaches 78%.γ-undecalactone's crude product was purified by vacuum batch distillation. On the premise of strict control of other conditions, the impact of reflux ratio on product purity and yield was focused on. Product purity would be more than 99% and yield 50% by introducing variable reflux ratios which was setted as 8 during the initial produced stage and as 12 during the late produced stage.The side effects of free radical addition reaction were also studied in this paper. Adding catalytic promoters including acids, zinc halide and inorganic salts has improved the product yield and other process operation parameters.The combined catalysts can improve the product yield, shorten the reaction time, lower the reaction temperature, reduce the consumption of n-butanol and decrease the contents of impurity in heavy component.