Synthesis of Alkyl Fructosides Using Solid Acid Catalysts. Part I: Silica-Alumina Cracking Catalysts

Abstract
Silica-alumina cracking catalysts and acid clays efficiently catalyze the 2-O-alkylation of d-fructose with long chain alcohols. Under the conditions applied virtually no degradation of fructose is observed. l-Sorbose and the aldopentoses also undergo silica-alumina-catalyzed alkylation. The rate of conversion is related to the solubility of the monosaccharide and the stability of the intermediate oxocarbenium ion. Best results in fructose alkylation are obtained by applying a recirculation method with butyl fructoside as soluble intermediate.