Asymmetric Reduction Of Natural Comphor

Recently, asymmetric synthesis of Alcohol from ketone compounds has been developed rapidly and some progress has been made. Alkali metals could be dissolved in solvents and form various systems to reduce many functional groups. Alkali metals become important reducers in organic reactions due to ease control of reaction temperature, moderation of reaction conditions and high yields.In this paper, the asymmetric reduction of camphor into D-borneol was carried out in Alkali metal natrium/alcohol system by taking advantage of the different molecular thermodynamical stability of midway products of camphor reduction. The experimental results indicated that the main product was D-borneol and the byproduct was isoborneol. The highlight of this dissertation was as follows:1)Reaction mechanism of reduction of camphor and the conditions and factors influencing reduction of camphor into D-borneol in alkali metal natrium/alcohol system was studied, and the optimal reaction condition was proposed. The experimental results indicated that there was about 62.8% D-borneol produced in natrium/alcohol system on the optimal reaction condition.2)Because of the reaction equilibrium restriction, there was lots of camphor in the product after the first reduction. The second reduction reaction technics was proposed based on the chemical equilibrium theory. We investigated and confirmed the optimal second reduction reaction condition. The conversion of comphor was about 98%, and the yield of D-borneol was about 81% after the second reduction reaction.3)The amplification tests of reducing comphor in the natrium/ alcohol system were designed and arranged. The experimental results indicated that although the conversion of comphor and the yield of D-borneol in the amplification tests was smaller than that in the uniform experiment, the reaction system tended to be stable after the second reduction reaction. This technics was still feasible after been amplified.4)The Infrared Absorption Spectrum of the product of the second reduction reaction was studied. The result indicated that the product's configuration was basically identical as the configuration that references presented. This showed that the product was D-borneol.5)The purity of byproduct sodium ethylate,recovered reagent ethanol and aether was analyzed and determined. The economic benefit of this technics that comphor was asymmetric reduced to produce D-borneol in the natrium/ alcohol system was analyzed and calculated in detail.