D-GLUCOSE AND RELATED MONOSACCHARIDES AS RAW MATERIALS

FOR ALKYL POLYGLYCOSIDES

Besides D-glucose,some related sugars may be interesting starting materials for synthesizing alkyl glycosides or alkyl polyglycosides. Special mention should be made of the saccharides D-mannose,D-galactose, D-ribose, D-arabinose,L-arabinose, D-xylose, D-fructose, and L-sorbose, which occur most frequently in nature or can be produced on an industrial scale. They are available at comparatively low prices and are therefore readily accessible as raw materials for the synthesis of surfactant alkyl glycosides, namely alkyl D-mannosides, alkyl D-galactosides, alkyl D-ribosides, alkyl D-arabinosides, alkyl L-arabinosides, alkyl xylosides, alkyl D-fructosides, and alkyl L-sorbosides.

D-glucose, also known as glucose, is the most famous sugar and the most common organic raw material. It is produced on an industrial scale through starch hydrolysis. D-glucose unit is the main component of plant polysaccharide cellulose and starch and household sucrose. Therefore, D-glucose is by far the most important renewable raw material for the synthesis of surfactants on an industrial scale.

Hexoses other than D-glucose, such as D-mannose and D-galactose, may be isolated from hydrolyzed plant materials. D-Mannose units occur in vegetable polysaccharides, so-called mannanes from ivory nuts, guar flours, and carob seeds. D-Galactose units are a main constituent of the milk sugar lactose and are moreover frequently found in gum arabic and pectins. Some pentoses are also readily accessible. The particular well-known D-xylose is obtained by hydrolyzing the polysaccharide xylan, which can be derived in large quantities from wood, straw, or shells. D-Arabinose and L-arabinose are widely found as constituents of plant gums. D-Ribose is bound as a saccharide unit in ribonucleic acids. Of the keto[1]hexoses, D-fructose, a constituent of the cane or beet sugar sucrose, is the best-known and most readily accessible saccharide. D-Fructose is produced as a sweetener in bulk quantities for the food industry. L-Sorbose is available on an industrial scale as an intermediate product during the industrial synthesis of ascorbic acid (vitamin C).