Synthesis of 3′-deoxy-4′-thionucleosides

Abstract

The racemic synthesis of 3′-deoxy-4′-thionucleosides, which are of interest as potential antiviral and antitumor drug candidates, was achieved. A key reaction involved a tandem intra- and intermolecular S_N2 reaction of a thioepoxide for constructing a 3′-deoxy-4′-thioribose skeleton. Pummerer reaction and subsequent Vorbrüggen-type glycosylation furnished 3′-deoxy-4′-thionucleosides. The proposed method is applicable for enantioselective synthesis using a commercially available chiral oxirane derivative.