One carbon homologation of carbohydrates by transcyanohydrination
AssigneeAllied-Signal Inc.
InventorBlaise J. Arena
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Abstract
A method of homologating monosaccharides via their cyanohydrins utilizes transcyanohydrination across a phase boundary from a water-insoluble donor cyanohydrin dissolved in an organic, water-immiscible solvent to an aqueous solution of a receptor monosaccharide. This heterogeneous transcyanohydrination can be incorporated into a cyclic process where the cyanide donor is enzymatically regenerated via enzyme catalyed addition of HCN to a suitable aldehyde. The latter process can be made continous or semicontinuous by immobilization of the enzyme.
Claims23
A method of transcyanohydrination of a monosaccharide comprising mixing a solution of a water-insoluble donor cyanohydrin in an organic solvent immiscible with water, said donor cyanohydrin being the adduct of the elements of hydrogen cyanide and a water-insoluble aldehyde, with an aqueous solution at a pH between about 7 and about 9 containing at least one monosaccharide so as to effect transfer of the elements of hydrogen cyanide from said donor cyanohydrin to the monosaccharide with formation of the cyanohydrins of the monosaccharide in the aqueous phase and regeneration of the water-insoluble aldehyde in the organic phase, and recovering the monosaccharide cyanohydrins.
The method of claim 14 where the pH is between about 7.8 and about 8.2.
A method of continuous transcyanohydrination of a monosaccharide comprising vigorously mixing in a first reaction zone a solution of a water-insoluble donor cyanohydrin in an organic solvent immiscible with water, said donor cyanohydrin being the adduct of the elements of hydrogen cyanide and a water-insoluble aldehyde, with an aqueous solution at a pH between about 7 and about 9 containing at least one monosaccharide so as to effect transfer of the elements of hydrogen cyanide from said donor cyanohydrin to the monosaccharide with formation of the cyanohydrins of the monosaccharide in the aqueous phase and regeneration of the water-insoluble aldehyde in the organic phase, recovering the aqueous phase containing the monosaccharide cyanohydrins, sending the organic phase to a second reaction zone wherein a solution of the water-insoluble donor cyanohydrin is regenerated by reaction of said aldehyde with hydrogen cyanide, and recycling the resulting solution of the donor cyanohydrin to the first reaction zone.
Dependencies are inferred from the claim text.