Study Of Photosensitized Catalytic Oxidation Of Some Monoterpeniods

Alpha-pinene, beta-pinene, limonene and citral are the best important monoterpeniods, which exist in turpentine oil, litsea cubeba oil, lemongrass oil and so on. The verbenone, myrtenal, myrtenol, carveol and carvone can be producted from monoterpenes. In this paper, the photosensitized oxidation and mechanism of the four monoterpenes were studied and the effects of photosensitizer, solvent, catalyst, and temperature were investigated. The reaction mechanism and selectivity of product were interpreted according to density function theory (DFT) from the molecular figuration. The excellent conclusions were obtained.1. The photosensitized oxidation of alpha-pineneIn the photosensitized oxidation of alpha-pinene, the conversion of alpha-pinene is gradually increased with time. The conversion of material is 97.67%; the selectivity of main product verbenone is 41.89% when the reaction, which RB was used as photosensitizer, methyl alcohol as solvent and 2, 6-lutidine and acetic anhydride as composite catalysts was carried for 38h at 303K. While the conversion is 98.50% and the selectivity of verbenone is up to 51.00% in DMF.2. The photosensitized oxidation of beta-pineneThe conversion of beta-pinene is 92.45%; the selectivity of myrtenal is 73.92% when the reaction which RB was used as sensitizer, methyl alcohol as solvent and 2,6-lutidine and acetic anhydride as composite catalysts, was carried for 47 hours at the temperature 303K. The conversion is 98.80% and the myrtenal selectivity is 85.16% in DMF.3. The photosensitized oxidation of limoneneIn the photosensitized oxidation of limonene, the conversion of limonene is 32.67% and the selectivity of main product...