Acid catalyzed reaction of 2-deoxy-3-O-methylsulfinylethyl-ribofuranosyl acetate with silyl enol ethers proceeded stereoselectively, resulting in the predominant formation of the corresponding β-C-glycosides.
β-C-2-Deoxyribofuranosides and β-S-2-deoxyribofuranosides are prepared stereoselectively from 1-O-acetyl-5-O-benzyl-3-O-[2-(methylsulfinyl)ethyl]-2-deoxy-d-erythro-pentofuranose or the corresponding 3-O-(2-pyridyl-methyl)pentofuranose N-oxide by the reaction with silyl enol ethers or trimethlsilyl sulfides in the presence of a Lewis acid.