Synthesis of furans from sugars via keto intermediates

A method of preparing 5-hydroxymethyl-2-furoic acid, the method comprising the steps of:

• (a) oxidizing glucose to provide gluconic acid by contacting the glucose with at least one enzyme to form the gluconic acid, wherein the at least one enzyme comprises at least one of a glucose oxidase and a glucose dehydrogenase;
• (b) dehydrating gluconic acid to provide 2-keto-3-deoxygluconic acid by contacting the gluconic acid with at least one enzyme to form the 2-keto-3-deoxygluconic acid, wherein the at least one enzyme comprises at least one of a galactonate dehydratase having the classification E.C. 4.2.1.6, an altronate dehydratase having the classification E.C. 4.2.1.7, a mannonate dehydratase having the classification E.C. 4.2.1.8, a dihydroxyacid dehydratase having the classification E.C. 4.2.1.9, a gluconate dehydratase having the classification E.C. 4.2.1.39, a glucarate dehydratase having the classification E.C. 4.2.1.40, a galactarate dehydratase having the classification E.C. 4.2.1.42, a D-fuconate dehydratase having the classification E.C. 4.2.1.67, a L-fuconate dehydratase having the classification E.C. 4.2.1.68, a xylonate dehydratase having the classification E.C. 4.2.1.82, a gluconate/galactonate dehydratase having the classification E.C. 4.2.1.140, and an L-galactonate dehydratase having the classification E.C. 4.2.1.146;
• and
• (c) dehydrating 2-keto-3-deoxygluconic acid to provide 5-hydroxymethyl-2-furoic acid.