SYNTHESIS AND REACTIONS OF UNSATURATED SUGARS

This chapter discusses the synthesis and reactions of unsaturated sugars. Sugar derivatives that contain double bonds have been developed and used so extensively that they almost certainly constitute the most versatile category of carbohydrate compounds available for use in synthesis of unsaturated sugars. They may be applied both in the synthesis of complex members of the family and of a myriad enantiomerically pure noncarbohydrate compounds—notably, many of interest in medicinal chemistry. In addition, some unsaturated sugar derivatives have themselves been found to possess important therapeutic properties. The unnatural L-nucleoside inhibits reverse transcriptase and shows potent and selective anti-AIDS activity. This chapter surveys the chemistry of most of the important types of monosaccharide derivatives that contain single alkene groups—notably, the glycols that are extremely valuable starting materials for a vast range of synthetic transformations. It also discusses the preparation of the reactions of glycols, elaborates the synthesis of pyranoid and furanoid 2- and 3-Enes, and explains the chemistry of endo-Enes and exo-Enes.