Process for making a mixture of L-glucose and L-mannose

Claim 1

A process for converting L-arabinose to a mixture of L-glucose and L-mannose comprising reacting L-arabinose with a source of cyanide at a temperature between about 10° and about 40° C., in an atmosphere of an inert gas, where the pH is maintained between about 7.0 and about 9.0 during the reaction, to afford a mixture containing the cyanohydrins of L-glucose and L-mannose, acidifying the solution of cyanohydrins with a nonpoisoning acid to a pH between about 1.0 and about 5.0 at a temperature no greater than about 25° C. in an atmosphere of an inert gas, hydrogenating the resulting solution using an effective amount of supported zerovalent palladium as a catalyst at a hydrogen Pressure no greater than about 80 psig, at a temperature between about 10° C. and about 50° C., and maintaining the pH between about 1.5 and about 2.5, and recovering the resulting mixture containing L-glucose and L-mannose.