ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Catalytic hydrogenation of D-xylose by using Raney-nickel catalyst

D. Tomkuljak

Slovak Tech. Univ., Bratislava

Abstract: D-Xylose was hydrogenated according to French 694,424 (C.A. 25, 1840) at 30° and 1 atm. in a 10% aq. soln. and in 50% MeOH, and the reaction rate const. measured. If D-xylose is hydrogenated in H₂O with 30% of Raney Ni, D-xylonic acid produced by the Cannizzaro reaction decreases the pH of the soln. and the activity of the catalyst. The reaction rate decreases continuously and the hydrogenation lasts 3-4 days. When the amt. of catalyst is increased from 3 to 30%, the Ca(OH)₂ from 0.5 to 1.5% (based on xylose), and the solvent 4 times, the pH of the soln. and the activity of the catalyst are not changed, and the reaction rate is kept const. Hydrogenation at 30° and 1 atm. lasts about 24 hrs. By increasing the temp. up to 70°, the reaction time is decreased to 7-8 hrs., and 90% of the theoretical amt. of xylitol free of Ni, b0.5 220-30°, is formed.

Full paper in Portable Document Format: 37a209.pdf (in Slovak)

Chemical Papers 3 (7) 209–224 (1949)