Tricyclic 2'-C-modified nucleosides as potential anti-HCV therapeutics.

Promising biological activity in a number of therapeutic areas has been reported for both tricyclic nucleosides and 2'-modified nucleosides. In particular, disubstitution at the C-2' position of nucleosides has resulted in significant activity against the hepatitis C virus (HCV). Combining this with the observation that tricyclic nucleosides developed in our laboratory have been shown to inhibit the RNA-dependent RNA polymerase NS5B led to the design of a series of 2'-modified tricyclic nucleosides. Details of the synthesis, structural characterization, and preliminary biological results are reported.