The Structure of γ-Sugars: Part VI: The Synthesis of a Furanose, a 6-Methylketohexose

Abstract

Abstract The γ-sugars are unstable and have not yet been isolated in the free state. They occur in nature only in glycosidal combination, e.g., in sucrose, inulin, graminin and in sinistrin, on hydrolysis of which only the normal form of the sugar is isolated. Derivatives of many of the hexoses and pentoses are known to exist in the γ-form. The simplest derivatives of these labile sugars are the glycosides, which have been found to differ widely in their chemical properties from those of the normal sugars. Thus they are susceptible to hydrolysis by very dilute mineral acid and can be distilled without decomposition in vacuo. Furthermore, the γ-glycosides reduce permanganate solution in the cold, a property which has not yet been shown by any of the glycosides of normal sugars.