柠檬酸催化合成2-正丙基-4,7-二氢-1,3-二噁庚英

以柠檬酸为催化剂,通过正丁醛与顺-1,4-丁烯二醇缩合反应合成了2-正丙基-4,7-二氢-1,3-二噁庚英。研究了醛、醇物质的量比、催化剂用量、反应时间、溶剂等对产品收率的影响。实验表明：在n醇：n醛=1：1.2;催化剂用量为醛的5%时,环己烷为带水剂,反应时间6 h的优化条件下,二氧七环产物的收率可达92%。

Synthesis of 2-Propyl-4,7-Dihydro-1,3-Dioxepine Using Citric Acid as Catalyst

Using citric acid as catalyst,2-propyl-4,7-dihydro-1,3-dioxepine was prepared by condensation reaction of butyric aldehyde and(cis)-2-butene-1,4-diol.The effects of the reactant ratio,catalyst amount,reaction time and the solvent on yiled were invesigated.Experiment results showed that the optimal conditions are:molar ratio is n(aldehyde) : n(2-butene-1,4-diol)= 1.2 : 1;the catalyst amount is 5% of the reactants;solvent is cyclohexane,reaction time is 6 h.The yiled was up to 92%.