Tautomerization

Tautomerization or enolization The process of shifting a hydrogen atom from one carbon atom to another to produce enediols is known as tautomerization. Sugars possessing anomeric carbon atom undergo tautomerization in alkaline solutions. When glucose is kept in alkaline solution for several hours, it undergoes isomerization to formD-fructose and D-mannose. This reaction- known as the Lobry de Bruyn-von Ekenstein transformatiorr-results in the formation of a common intermediate-namely enediol--$or all the three sugars. The enediols are highly reactive, hence sugars in alkaline solution are powerful reducing agent Ref: Biochemistry by U. Satyanarayana 3rd edition Pgno : 16,17