【作者】 王小梅；

【导师】 李谦和； 尹笃林；

【作者基本信息】 湖南师范大学 ， 应用化学， 2003， 硕士

【摘要】 光学活性紫苏醇的合成及其选择性氧化研究是开发我国丰富的松节油资源，利用松节油合成一系列精细化学品的一条重要途径。以松节油中的主要成分β-蒎烯的环氧化合物2，10-环氧蒎烷为原料，经催化重排合成紫苏醇，紫苏醇不仅可作为一种单体香料，还可作为一种重要的有机反应中间体，用来合成一系列更有价值的香料化合物。如紫苏醇选择氧化合成紫苏醛，紫苏醛肟化得到一种高甜度、低热值、味质好、无毒副作用的新型食品添加剂紫苏葶等。 利用β-蒎烯的环氧化合物2，10-环氧蒎烷的开环重排合成紫苏醇是文献报道过的最简易的方法。但该方法在工业生产中存在如紫苏醇产率低、反应过程中原料的聚合量大、产物不易分离等缺点。本文系统研究了2，10-环氧蒎烷液相催化重排的反应规律，对合成紫苏醇的工艺进行了新的探索；同时对紫苏醇在活性MnO₂、CrO₃／SiO₂载体试剂和重铬酸钠三种氧化剂的作用下进一步选择氧化合成紫苏醛进行了探索性研究，获得了一些有应用价值的结果。 1．研究了2，10-环氧蒎烷液相重排的反应规律和产物分布，考察了反应温度、反应时间、溶剂用量、溶剂、溶剂中的含水量等对重排反应的影响。结果表明：在酸催化剂存在下，强极性非质子溶剂中，2，10-环氧蒎烷于353-363 K可定向重排生成紫苏醇。一定条件下反应，2，10-环氧蒎烷的转化率为98.9％，紫苏醇产率为43.8％，原料的聚合量为39.6％； 2．以固定床反应工艺代替传统的搅拌釜式反应，考察了空速、反应温度、溶剂用量对重排反应的影响。结果表明：固定床反应合成紫苏醇在降低2，10-环氧蒎烷聚合量、提高紫苏醇的产率、简化产物分离等方面比传统的间歇搅拌釜式反应器优越。当反应温度为353 K，空速为1.5／h，溶剂用量与2，10-环氧蒎烷体积比为8：1时，2，10-环氧蒎烷的转化率达到91.2％，紫苏醇产率为69.9％，原料的聚合量接近于0； 3.研究了活性MnOZ、Cr03/510:载体氧化试剂和重铬酸钠液相选择性氧化紫苏醇合成紫苏醛的反应。结果表明:活性MnO:可以选择性氧化紫苏醇生成紫苏醛，以乙酸乙醋作溶剂，氧化反应温度控制在328K一溶剂回流温度之间，紫苏醇与氧化剂的质量比为1:4，搅拌反应4h，紫苏醇转化率可以达到997%，紫苏醛产率达70%以上;用干混法制备的CrO3/510:载体试剂是紫苏醇液相选择性氧化合成紫苏醛的高效氧化剂，以二氯甲烷作溶剂，CrO3/510:载体氧化剂的负载量为2 mmol/g，氧化剂与紫苏醇的摩尔比为2.5:1，室温下搅拌反应90 min，紫苏醇转化率达到95.0%，紫苏醛产率为57.9%;用NaZCrZO:作氧化剂，采取边反应边蒸馏的实验工艺，通过三水平三因素Lg（3，）的正交试验，优化条件下反应，紫苏醛的产率达到40.0%。更多还原

【Abstract】 Studies on synthesis and selective oxidation of optical perillyl alcohol are an important procedure to develop abundant turpentine oil of our country and to synthesize a series of fine chemicals. Perillyl alcohol is obtained from rearrangement of 2,10-epoxypinane, which is prepared by epoxidation of 3 -pinene. 3 -pinene is a crucial component of turpentine oil. Perillyl alcohol can be used not only as a kind of flavor but also as an important organic intermediate to produce a series of more important flavors and perfumes. For example, Perillyl aldehyde can be prepared by selective oxidation of perillyl alcohol, and perillatine, obtained from oxidation of perillyl aldehyde, is a sort of new food additive with properties of high sweetness, low caloricity, good flavor and without toxin etc. Synthesis of perillyl alcohol by rearrangement of beta-pinene epoxide is the simplest method reported by literature from 1970 to 2002. But there are some shortcomings in industry production such as low yield of perillyl alcohol, high degree of polymerization, tedious separation of products and so on. In this thesis, rearrangement reaction of 2,10-epoxypinane and selective oxidation of perillyl alcohol are investigated. Some valuable results are obtained as follows:1. The reaction and the product distribution of liquid isomerization of 2,10-epoxypinane are studied. Effects of reaction conditions on isomerization are investigated. It is discovered that isomerization of 2,10-epoxypinane produce mainly perillyl alcohol in 353 ~ 363 K catalyzed by acid catalysts in strongly polar protonic solvent. Perillyl alcohol can be obtained with 43.8% yield, 98.9% conversion of 2,10-epoxypinane and 39.6% polymerization in optimum condition.2. Effects of reaction conditions on isomerization in fixed bed are also studied. The results show that synthesis of perillyl alcohol in fixedbed is better than in stirred reactor in reducing degree of polymerization, improving yield of perillyl alcohol and simplifying separation of products. Perillyl alcohol can be obtained with 69.9% yield, 91.2% conversion of 2,10-epoxypinane and degree of polymerization is near to 0 in the optimum conditions in 353 K, 1.5/h space velocity and the volume ratio of solvent to 2,10-epoxypinane is 8 to 1.3. Selective oxidation of perillyl alcohol to perillyl aldehyde is studied in the presence of active MnO2, CrO3/SiO2 supported oxidant and Na2Cr2O7. The results show that active MnO2 can be used to oxidize perillyl alcohol to perillyl aldehyde selectively, and conversion of perillyl alcohol is 99.7%, yield of perillyl aldehyde is over 70% in optimum reaction condition with ethyl acetate as solvent, under solvent reflux temperature for 4 h, the mass ratio of oxidant to perillyl alcohol is 4 to 1. CrCVSiO2 supported reagent, prepared by dry mixing method, is an efficient oxidant which oxidize perillyl alcohol to perillyl aldehyde in liquid phase under mild conditions, and conversion of perillyl alcohol is 95.0%, yield of perillyl aldehyde is 57.9% with dichloromethane as solvent under room temperature for 90 min, the ratio of oxidant to perillyl alcohol is 2.5 to 1, loading of CrO3 is 2 mmol/g. The yield of perillyl aldehyde is 40.0% in optimum reaction conditions by 33-orthogonal experiments with the technology of distillation by Na2Cr2O7 oxidant.更多还原