2-己基-4-乙酰氧基四氢呋喃顺反异构体的制备

Preparation of trans- and cis-2-hexyl-4-acetoxytetrahydrofuran

摘要:

本文研究了2-己基-4-乙酰氧基四氢呋喃顺反异构体的制备方法。首先以烯丙基氯和庚醛为原料通过格氏反应制得1-癸烯-4醇，产率86%；1-癸烯-4醇用间氯过氧苯甲酸氧化，得到1,2-环氧-4-癸醇，产率89%；然后在碳酸钾的作用下1-癸烯-4醇进行分子内的亲核取代反应，关环得到2-己基-4-羟基四氢呋喃顺反异构体的混合物，产率90%，trans-和cis-异构体比例为53/47；2-己基-4-羟基四氢呋喃与对硝基苯甲酰氯反应，酯化产物通过柱层析分离，得到trans-和cis-2-己基-4-四氢呋喃对硝基苯甲酸酯，产率分别为52%和40%；分离后的酯化产物的顺反异构体在碱性条件下水解，得到trans-和cis-2-己基-4-羟基四氢呋喃，产率分别为85%和82%；trans-和cis-2-己基-4-羟基四氢呋喃和乙酸酐反应，得到trans-和cis-2-己基-4-乙酰氧基四氢呋喃，产率分别为83%和85%。trans-和cis-2-己基-4-乙酰氧基四氢呋喃经过GC-O进行了评香分析和稀释因子的测定，结果表明两者具有不同的香气特征和香气强度。

Abstract:

The preparation of cis- and trans-2-hexyl-4-acetoxytetrahydrofuran has been studied. 1-Decen-4-ol was obtained in 86% yield by the Grignard reaction starting from allyl chloride and heptanal, which was then epoxidized by m-chloroperoxybenzoic acid to give 1,2-epoxy-4-decanol in 89% yield. The cis- and trans-2-hexyl-4-hydroxytetrahydrofuran mixture was produced in 90% yield through an intramolecular nucleophilic substitution of 1,2-epoxy-4-decanol promoted by K2CO3. The ratio of trans- and cis-isomer was 53/47. 2-Hexyl-4-hydroxytetrahydrofuran reacted with p-nitrobenzoyl chloride and the products of esterification were separated by column chromatography to give trans- and cis-isomer individually in 52% and 40% yield respectively. The trans- or cis-ester was hydrolyzed in a basic solution to give trans- or cis-2-hexyl-4-hydroxytetrahydrofuran in 85% or 82% yield. trans- or cis-2-Hexyl-4-acetoxytetrahydrofuran was produced after acetylation with Ac2O in 83% or 85% yield. The odor and flavor dilution factor of trans- or cis-2-hexyl-4-acetoxytetrahydrofuran were evaluated by GC-O, which indicated that two isomers differed in odor feature and odor intensity.