Zweifel Olefination for C-Glycosylation

Starting from glycal derivatives, the Zweifel olefination presents an elegant opportunity to access C-glycosides in a selective manner. a-Lithiation of D-glucal, L-rhamnal, D-xylal and L-arabinal scaffolds was employed as a starting point in the synthesis of corresponding unsaturated aryl-, heteroaryl- and alkenyl-C-glycosides. This provides a straightforward strategy towards pharmacorelevant gliflozins and other unreported rhamnal- and xylal-analogs.