Hexose sugars undergo smooth coupling with 1,3-diketones and β-keto esters in the presence of 10 mol% of indium(III) chloride in water at 80 °C to furnish C-furyl glycosides in excellent yields, whereas pentose sugars produce trihydroxyalkyl-substituted furan derivatives with high selectivity. The reactions of cyclic ketones such as cyclohexane-1,3-dione or dimedone with d-glucose in acetonitrile at 80 °C gave the corresponding tetrahydrobenzofuranyl glycosides derivatives.
aldose - indium(III) reagents - 1,3-diones - (trihydroxyalkyl)furan - C-glycosidation
