Anhydro sugars chromatography

In a similar approach, treatment of methyl glycosides with camphorsulfonic acid (CSA) in toluene under Dean-Stark conditions provides a good route to functionalized 1,6-anhydro sugars. Heathcock and co-workers showed that oxidation of the difficult-to-separate mixture of the l,6-anhydro- 8-D-glucopyranose (6) and l,6-anhydro- 8-D-glucofuranose (7) allowed for easy isolation of the desired ketone (8), by either chromatography or direct crystallization, depending on the reaction scale (O Scheme 4) [21]. 

Other carbohydrate derivatives that have been examined by gas-liquid chromatography include anhydro sugars of both the epoxide and 3,6-anhydro type, and isomeric methyl (ethylthio)furanoside diacetates" and their desulfurized derivatives."... 

These derivatives of the monosaccharide structural units are then qualitatively and quantitatively analyzed by gas chromatography on capillary columns. In more difficult cases, a preliminary separation of acidic and neutral polysaccharides on an ion exchanger is recommended. Methanolysis or hydrolysis of polysaccharides containing uronic acids and anhydro sugars are critical due to losses of these labile building blocks. 

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