| 摘要 |
<p>L-arabinose is converted into L-glucose/L-mannose mixtures by formation of L-mannose and L-glucose cyanohydrins at a controlled pH of 7 to 9 using a cyanide source in an inert atmosphere at a temperature of 10 to 40 DEG C and, after acidification to a pH of 1 to 7 the product is selectively hydrogenated at controlled conditions, using supported zerovalent palladium as catalyst, a temperature of 10 to 50 DEG C and a hydrogen pressure not greater than 550 k Pa g, to selectively convert the cyano group to the imine group with subsequent hydrolysis to the aldehyde group without any significant hydrogenation of the latter. The resulting L-glucose/L-mannose mixtures can be converted to L-fructose by isomerisation in the presence of a base. </p> |
