Samarium Diiodide-Mediated Reductive Coupling of Epoxides and Carbonyl Compounds: A Stereocontrolled Synthesis of C-Glycosides from 1,2-Anhydro Sugars

Sugar mimics: 1,2-anhydro sugars can be cross-coupled with aldehydes and ketones under very mild conditions and using a wide range of protecting groups to give C-glycosides in good yield in a radical reaction mediated by SmI2 (see scheme; A=no proton source, B=in the presence of water).