Research Of The Catalytic Epimerization Of L-arabinose

In this paper, the abstraction of L-arabinose, the preparation of the L-ribose and theapplications of the two substances were summarized. The L-arabinose was abstracted fromthe Arabic gum. The influence of the temperature, neutralization and ferment condition wasdiscussed. The optimized conditions of the reaction were studied in detail. Gum Arabic ishydrolyzed by H2SO4, and after neutralization, ferment and reacted with aniline, the crudesugar mainly including L-arabinose can be obtained. The purity of the L-ribose afterrecrystallization was 95.9%, and the total yield was 29.5%. The L-arabinose was used toprepare the L-ribose by the course of catalytic epimerization. The influence of the catalyst,temperature and the reaction time were studied to get the optimum conditions of the reaction.Also, the separation condition of the reactant mixture was discussed. With the catalysis ofthe trioxidmolybdenum and 4-pyridinepropanol the obtained L-arabinose experienced theepimerization in 90℃ for 3 hours to get the L-ribose. After crystallization we can get theL-ribose, m.p. 83⁸4℃, the result of polarimetric analysis was [α]²⁰_D=+20.7°, and thetotal yield was 10.7%.