2-己基-4-乙酰氧基四氢噻吩顺反立体异构体制备及香气特性

Preparation and Aroma Characteristics of Cis-trans Stereoisomers of 2-Hexyl-4-Acetoxy-tetrahydro-thiophene

文章以烯丙基氯和正庚醛为原料,首先将烯丙基氯制成烯丙基氯化镁,与正庚醛经格氏反应得到1-癸烯-4-醇,产率为87%;1-癸烯-4-醇用间氯过氧苯甲酸氧化,转变为1,2-环氧-4-癸醇,产率为93%;环氧醇在三乙胺的作用下与甲磺酰氯反应,得到1,2-环氧-4-癸基甲磺酸酯,产率为78%;1,2-环氧-4-庚基甲磺酸酯在碳酸钾存在下与硫代醋酸反应,得到2-己基-4-乙酰氧基四氢噻吩的两个顺反立体异构体,产率分别为39%和43%。产物的顺反相对构型经过NOE谱图进行了确认。两个顺反立体异构体的香气特征和香气阈值通过GC/O进行了评价和测定,两个异构体表现出明显不同的香气特性。

In this paper,allyl chloride and n-heptaldehyde are used as the raw materials.Firstly,allyl chloride is made into allyl magnesium chloride,and then 1-decane-4-alcohol is obtained by Grignard reaction with n-heptaldehyde of 87%yield.1-decane-4-alcohol is oxidized with m-chloroperoxybenzoic acid and converted to 1,2-epoxy-4-decanol of 93%yield.Epoxy alcohol reacts with methylsulfonyl chloride under the action of triethylamine to obtain 1,2-epoxy-4-decanol methyl sulfonate with 78%yield.Two cis-trans stereoisomers of 2-hexyl-4-acetoxy-tetrahydro-thiophene are synthesized by the reaction of 1,2-epoxy-4-heptamethylsulfonate with thioacetic acid in the presence of potassium carbonate,the yield is 39%and 43%respectively.The cis-trans configuration of the product is confirmed by NOE spectrogram.The aroma characteristics and aroma thresholds of the two cis-trans stereoisomers are evaluated and determined by GC/O.The two isomers show distinctively different aroma characteristics.