Sulfuric acid immobilized on silica: an excellent catalyst for Fischer type glycosylation

Fischer glycosylation, a widely used technique for the preparation of simple alkyl or aryl glycosides, has a few drawbacks including the use of strong mineral acids, excess alcohols, high temperature and long reaction times. This manuscript highlights a modification using sulfuric acid immobilized on silica as catalyst for the preparation of glycosides from free sugars such as d-glucose, d-galactose, d-mannose, l-rhamnose, l-fucose, N-acetyl-d-glucosamine and d-maltose with a diverse range of alcohols to afford a series of useful sugar derivatives in good to excellent yields.