The Preparation and Reactions of 3,6-Anhydro-D-Glycals

Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ, 

The properties of anhydrosugars make them useful as protecting groups that, under the appropriate conditions, can enable them to serve as reactive intermediates for the formation of new C-C and C-X bonds. These characteristics have made them useful precursors for the formation of a variety of carbohydrate derivatives and medicinally important compounds. For example, anhydrosugars have been utilized in 

Domino and Intramolecular Rearrangement Reactions as Advanced Synthetic Methods in Glycoscience, First Edition. Edited by Zbigniew J. Witczak and Roman Bielski. 

SCHEME 12.1 Formation of a 3,6-anhydrosugar in the presence of added base. 

Several reducing agents have been utilized to remove tosylate esters of sugars and other polyols. In particular, lithium aluminum hydride and lithium triethylborohydride have been most extensively used [20-23]. When secondary alcohol tosylates are used, epoxide intermediates are frequently involved. Reduction is observed to occur through either C-0 or O-S bond cleavage [24]. In this chapter, we discuss our results from the reduction of 6-0-tosylates of D-glucal and D-galactal with lithium aluminum hydride in THF. 

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