A Study Of The Modification On Acidic Catalysis In The Isomerization Of Monoterpenoids

The deep and fine processing of the renewable resources such as pine resin and otherwise is possessed of outstanding signification on the sustainable development. It can not only exploit resource and avail of the solar energy but also drive the farmers in the mountain district to augment their income. The thesis presents some new explores and significant results for the isomerization of a-pinene and the rearrangement of P-pinene epoxide, through the designing and sieving of the catalysts, the investigation of the rule of the catalytic reactions, and the experiments by poisoning.1. The new methods for the catalytic isomerization of a-pinene Considering the importance of limonene in preparations of perfumes, fragrances, bioactive compounds, and functional materials, the effects of varied acidic catalysts including carboxylic acids, sulfonic acids, and heteropoly acids, different solvent, reaction temperature, and reaction time on the catalytic isomerzation of a-pinene were investigated systematically in order to increase the selectivity of limonene in the reaction. It was disclosed that the solid acid based on active carbon possesses an obvious catalytic performance on the isomerzation ofa-pinene, of which the surface was carboxylated through the modesty oxidation by nitric acid and hydrogen peroxide. Based on the reaction mechanism and the difference among the boiling points of themonoterpene, a method of catalytic distillation was built in the isomerzation of a-pinene for using the carboxylation particle carbon as catalyst. The new catalytic process makes contributions to increase the selectivity of limonene, and possesses the peculiarities of high stability and longevity. The toxical results of molecule probe revealed that the carbon solid acid is a kind of protonic acid catalyst.2. The new method for the catalytic rearrangement of p-pinene epoxideBecause of wide use of the product derived from P-pinene epoxide in the plant medications possessing more extensive anticancer active and the preparation of perillaalcohol (a kind of no calorific value sweetener), some new procedures for the rearrangement of P-pinene epoxide were explored in this thesis. The effects of varied catalysts including ammonium nitrate, ammonium phosphomolybdate, and ammonium phosphomolyvanadate and different solvents on the catalytic rearrangement of p-pinene epoxide were studied. It was found that the formation of myrtenol could be reduced by using ammonium phosphomolybdate as catalyst and the mixed solvents in the rearrangement reactions on P-pinene epoxide, increasing the selectivity of perillaalcohol. The pyridine poisoning experiments revealed that the catalyst is possessed of strong antienvenom ability, ,v.The results from this work will provide a base for developing thenew technology to synthesize fine chemicals from turpentine oil.