Stereoselective synthesis of glycosides

2-Deoxyglycosides are an important class of carbohydrates which are devoid of functionality at the C 2 position. This ubiquitous class of chiral acetals are found in various natural products, such as the anticancer compounds Landomycin A and Lomaiviticin A. The challenges for their synthesis include the fact that most stereoselective glycosylations employ a group at C-2 to direct nucleophilic attack via neighbouring group participation, making such methods inapplicable. A general approach based on reagent-controlled rather than substrate-controlled glycosylation to achieve stereoselectivity would therefore be an important development.

To this end, we propose the development of new catalytic methods for the stereoselective generation of alpha- and beta-glycosides, and the subsequent use of such protocols in the synthesis of biologically-relevant oligosaccharides. We intend to develop generally applicable methods for the synthesis of all types of glycosides, including 2 deoxyglycosides, 2,6-deoxyglucosides, 2-deoxy-2-aminoglycosides and (through our collaborators in Illinois) sialilated glycosides, a class of carbohydrates for which no general methods for achieving stereocontrol exist.