龙脑合成方法的改进

The optimum conditions for the synthesis of borneol via the reaction of α-pinene and oxalic acid in the presence of nanometer solid superacid catalyst SO2-4/ZrO2 were obtained. The results show that when the mole ratio of α-pinene to oxalic acid was 1∶0.4, the mass fraction of the catalyst SO2-4/ZrO2 to （α-pinene） 3%, the reaction time 6 h, and the reaction temperature program was 65 ℃ for 1 h, 75 ℃ for 4 h, 90 ℃ for 1 h, the yield of crude product （borneol） reached 70.9%. This method offers little pollution, high yield, mild （reaction） condition, good processing safety, and catalyst reusability.