(-)-薄荷酮的制备及比旋光度测定——介绍一个研究型有机化学实验

Synthesis and Specific Rotation Determination of(-)-Menthone:A Research-Oriented Fundamental Organic Chemistry Experiment

以(-)-薄荷醇为原料,采用重铬酸钠或次氯酸钠为氧化剂制备(-)-薄荷酮,比较了不同氧化方法的特点。测定了产物的比旋光度,并通过气相色谱对实验结果进行了分析,讨论了(-)-薄荷酮与(+)-薄荷酮之间的差向异构化作用对比旋光度的影响。本实验涉及加热回流、蒸馏、萃取、过滤等基本操作以及气相色谱表征与比旋光度的测定与分析,有利于培养学生基本操作技能,培养综合分析能力。

(-)-Menthone has been prepared by oxidation of(-)-menthol with sodium dichromate in dilute sulfuric acid or sodium hypochlorite in acetonitrile,and the preparation methods have been reviewed briefly.The specific rotation of(-)-menthone was determined and discussed with respect to the epimerization between(-)-menthone and(+)-menthone,which was corroborated by gas chromatography.This experiment covers the training in fundamental experimental skills such as reflux,distillation,extraction,filtration,gas chromatography characterization and specific rotation determination,and may help the undergraduates improve their integrative abilities and learn the knowledge of chiral compounds.