| abstract |
The invention relates to a method for producing alpha-hydroxy-beta-ene-acids or their esters, namely, to obtain 2,5,6-trihydroxy-3-hexenoic acid and 2,5-dihydroxy-3-pentenoic acid and their esters where the values of R and R 'are indicated in the description of the invention, and the specified method includes the steps: a) contacting a saccharide composition containing one or more C6 and / or C5 saccharide units, with a material based on Lewis acid; and b) isolating 2,5,6-trihydroxy-3-hexenoic acid and / or 2,5-dihydroxy-3-pentenoic acid or their esters, said saccharide composition comprising one or more C6 and / or C5 saccharide units , is selected from the group consisting of sucrose, xylose, mannose, tagatose, galactose, glucose, fructose, arabinose, inulin, amylopectin and sugar syrup, and wherein the concentration of alkali metal ions present in the medium of the Lewis acid material is kept at the concentration level less than 0.13 mM or less than 0.5 wt.% of the weight of the Lewis acid-based material. |