Study On The Liquid Isomerization Of 2, 10-Epoxypinane

Perillyl alcohol, a useful flavor and an important organic intermediateto produce perillyl aldehyde and preillartine, has great beneficial effectsin the treatment and prevention of cancer. Synthesis of perillyl alcohol byisomerization of 2,10-epoxypinane has been proven to be the simplestmethod. The reaction and the rearrangement product distributions havebeen investigated in our lab over the past few years. It was discoveredthat the reaction was influenced by the reaction time, reaction temperature,amount of solvent and by the structure of the catalyst. Recently, weobtained some valuable results about the rearrangement productdistributions of isomerization of 2,10-epoxypinane by studying thedesign and preparation method of the catalysts, solvent effects and so on.1. A series of nitrate catalysts with the pK_a values ranging from -4~11 have been prepared. It was discovered that nitrate catalysts exhibitexcellent catalytic performance at pH values between 8~11. The factorinfluencing the selectivity of the reaction was the steric hindrance effectof the cation in the catalyst that the structure more closely resembledwith perillyl alcohol, the better the selectivity and yield of perillylalcohol. For example, the selectivity of perillyl alcohol could be up to84.44% , 85.66% and 89.79% with Cyclohexylamine nitrate,benzylamine nitrate and urea nitrate as catalysts, respectively. Thebi-active sites catalyst was also investigated in this paper, whichprovided a new way to obtain perillyl alcohol with high selectivity. In aword, the rearrangement product distributions of 2,10-epoxypinaneresulted from both the acidity and the steric hindrance effect of thecation in the catalyst.2. The preparation process and the disperse state of the ammonium nitrate catalyst were studied in detail in this paper. Besides these, the solvent effect on the reaction and the rearrangement product distributions were also investigated. It was found that perillyl alcohol was obtained as the main rearrangement product in strong polar protonic solvent and myrtenol as the main rearrangement product in weak polar non-protonic solvent. The selectivity for perillyl alcohol is over 80% in CH3NO2, and the selectivity of myrtenol is over 70% in CH3CC13 under the optimized conditions.3. We also studied the influences of the anion in the catalyst in the isomerization reaction where NH4CI and CH3COONH4 have relatively good activity and high selectivity to perillyl alcohol. 95.10% conversion of 2,10-epoxypinane could be reached after 8h when NH4CI acts as the catalyst, but the selectivity of perillyl alcohol and myrtenol were only 33.35% and 38.96%, respectively. The findings concerning anions provided a theory guide for designing and preparing new catalysts.