Radical-based transformation of vicinal diols to olefins via thioxocarbamate derivatives: a simple approach to 2′,3′-didehydro-2′,3′-dideoxynucleosides

The bis-O-thioxocarbamate derivatives obtained from the reaction of vicinal diols with phenyl isothiocyanate are shown to be reduced with tris(trimethylsilyl)silane in the presence of azobisisobutyronitrile to afford the corresponding olefins in good yields. In this way, 2′,3′-didehydro-2′,3′-dideoxy analogs of adenosine, guanosine, inosine, cytidine and uridine were prepared by the radical-based deoxygenation of the corresponding ribonucleosides via the bis-O-thioxocarbamate derivatives.