β-熊果苷的合成

The Synthesis of β-Arbutin

利用Helferich原理,以对苯二酚和α-D-葡糖糖为起始原料,通过乙酰化保护、缩合、二次乙酰化以及脱保护等反应合成制备β-熊果苷。对制备β-五乙酰葡糖过程的催化剂、反应条件、重结晶方法进行了研究,优化条件下得到β-五乙酰葡糖,无α型残留,纯度100%,收率达到75.6%;此外,还对缩合反应重新设计,对苯二酚无需先乙酰化,直接与β-五乙酰葡糖缩合后乙酰化,并对反应过程中的溶剂、催化剂、投料比、反应时间进行了研究,两步合并,优化条件下β-五乙酰熊果苷的收率达到80%;最后通过脱保护得到β-熊果苷,纯度99.9%,收率80%,熔点与文献相符,其结构经1H NMR表征确认。反应均在常压下进行,收率高,原料易得,操作简单,既适用于实验室小规模制备,也适合大规模工业化生产。

Abstract： Based on the principle of Helferich reaction, β-arbutin was obtained from hydroquinone and or-D-glucose as the starting material via acetylation, condensation,secondary acetylation and deacetylation. The optimal condition was confirmed by studied, catalyst, temperature, recrystallization on the preparation of β-D-glucopyranosyl pentaacetate, and get β-D-glucopyranosyl pentaacetate with no α type residual, purity of 100%, yield of 75.6%. In addition, the new design of condensation reaction was that the acetylation of hydroquinone was after the condensation of hydroquinone and β-D-glucopyranosyl pentaacetate. The effect of solvent, catalysts, mole ratio of reactants, reaction time and reaction temperature on the yield were investigated. The two steps together optimized yield was 80%. Finally through the deprotection got β-arbutin with purity of 99.9% and yield of 80%, melting point of the compound were consistent with those reported, and the structure of product was confirmed by 1H NMR. The reaction can proceed well at atmospheric pressure, easy to gain materials and the yield was high,and simple to operate. This method is suitable for preparation on a small scale in the laboratory, also suitable for large-scale industrial production.