Turanose properties

Alekhine had mentioned that turanose reacts with phenylhydrazine. Maquenne prepared the phenylosazone and described its precipitation from water in the flocculent or gel condition that is so very characteristic of the substance, but he did not report an analysis. A year after Ma-quenne s publication, Emil Fischer16 examined a small sample of amorphous turanose which had been sent by Dr. Konowaloff of Moscow. Its phenylosazone was prepared in good crystalline form by several recrystallizations from aqueous alcohol the analysis of these crystals proved conclusively the disaccharide formula for turanose which Alekhine had proposed from the analysis of amorphous substances. The writer had occasion recently to prepare turanose phenylosazone in considerable quantity its very characteristic properties and those of the derived phenylosotriazole are described on pages 27 and 28. 

Reducing oligosaccharides show many of the properties of simple sugars such as mutarotation, reduction of alkaline solutions of salts of heavy metals, existence of and p)ranose and furanose isomers, and ready oxidation and reduction. Nonreducing sugars behave as alcohols unless the linkages are hydrolyzed by acids. The linkages are usually stable to the action of alkalies, but a few (e.g., turanose) are alkali-labile. 

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