Halogenated carbohydrates Sugars

The search for new methods of synthesis of halogenated carbohydrates continues to be an active area of investigation. The compounds are of utility as synthetic intermediates, and many of them are of intrinsic value in biochemistry and pharmacology. In the present Chapter methods for the synthesis of deoxyfluoro sugars and glycosyl fluorides are discussed. 

Lemmes R, von Sonntag C (1982) On the formation of deoxy sugars from halogenated carbohydrates by a-hydroxyalkyl radicals considerations for the optimisation of reaction conditions. Carbohydr Res 105 276-282... 

Barker, S. A., and Bourne, E. J., Acetals and Ketals of the Tetritols, Pentitols and Hexitols, 7, 137-207 Barnett, J. E. G., Halogenated Carbohydrates, 22, 177-227 Barnett, J. E. G., and Corina, D. L., Sugars Specifically Labeled with Isotopes of Hydrogen, 27, 127-190 Barrett, Elliott P., Trends in the Development of Granular Adsorbents for Sugar Refining, 6, 205-230 Barry, C. P., and Honeyman, John, Fructose and Its Derivatives, 7, 53-98... 

The incorporation of heteroatoms can result in stereoelectronic effects that have a pronounced effect on conformation and, ultimately, on reactivity. It is known from numerous examples in carbohydrate chemistry that pyranose sugars substituted with an electron-withdrawing group such as halogen or alkoxy at C-1 are often more stable when the substituent has an axial, rather than an equatorial, orientation. This tendency is not limited to carbohydrates but carries over to simpler ring systems such as 2-substituted tetrahydropyrans. The phenomenon is known as the anomeric ect, because it involves a substituent at the anomeric position in carbohydrate pyranose rings. Scheme 3.1 lists... 

The increased availability of methods for the preparation of unsaturated sugars107 has stimulated interest in addition reactions of these compounds the use of unsaturated carbohydrate derivatives as precursors for specifically halogenated sugars has been widely exploited. 

J. E. Barnett, Halogenated sugars, Adv. Carbohydr. Chem. 22M1 (1967). 

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