NO128715B

1,236,910. Xylose and xylitol. F. HOFFMANN-LA ROCHE & CO. A.G. 22 July, 1969 [26 July, 1968], No. 36685/69. Heading C2C. Xylose and xylitol are prepared by treating a material containing xylan and cellulose, e.g. grasses, and wood from deciduous trees such as beech, oak and ash, with a 1 to 5% aqueous oxalic acid solution at a temperature of 50‹ to 130‹ C. and, if desired, reducing the resulting xylose, preferably after decolorization and deacidification, to xylitol. The starting material is preferably fractionally washed with water at about 100‹ C. before treatment with the oxalic acid solution. The treatment with oxalic acid solution may be effected in two stages, the first using a 1% oxalic acid solution at about 100‹ C. and the second using a 3% oxalic acid solution also at about 100‹ C. The xylose may be decolorized and deacidified by filtration through a basic ion-exchange resin and then reduced by hydrogenation in the presence of Raney nickel at about 105-110‹ C. and 30 atmospheres to form xylitol.