Patent ID: 7439046

Claim:
A process of making 4-hydroxy-tetrahydropyran-2-one comprising converting 2,4-dideoxyhexose or 2,4,6-trideoxyhexose into the corresponding 4-hydroxy-tetrahydropyran-2-one wherein the 2,4-dideoxyhexose and 2,4,6-trideoxyhexose is obtained from the process comprising providing a reaction mixture of a substituted or unsubstituted carbonyl compound containing at least 2 carbon atoms and at least one α-hydrogen atom and a substituted or unsubstituted aldehyde in the presence of an aldolase and water, wherein the carbonyl concentration is at most 6 moles/liter of the reaction mixture to form 2,4-dideoxyhexose or 2,4,6-trideoxyhexose, and wherein the final concentration of the 2,4-dideoxyhexose or the 2,4,6-trideoxyhexose is at least 2 mass % of the reaction mixture, and wherein the substituted or unsubstituted aldehyde is of the formula HC(O)CH 2 X, where X represents a leaving group.