Highly stereoselective synthesis of 2′-deoxy-β-ribonucleosides via a 3′-(N-acetyl)-glycyl-directing group

A facile synthesis of 2′-deoxy-β-ribonucleosides from 3′-O-(N-acetyl)-glycyl-protected 2′-deoxyribofuranose has been developed. The coupling reactions between the protected 2′-deoxyribose and silylated bases exhibited β-selectivity up to 98% presumably via a 1′,3′-participation mechanism. The 3′-directing group can be introduced and removed easily under mild conditions. This approach provides an efficient and highly stereoselective entry for the synthesis of 2′-deoxy-ribonucleosides.