2′(β)-Hydroxyethylated adenosine is a potent and selective inhibitor of hepatitis C virus (HCV) replication targeting the RNA-dependent RNA polymerase of HCV, NS5B. The synthesis and anti-HCV evaluation of carbodine analogues are described. The cyclopentene intermediate 10 was successfully made via sequential Johnson-Claisen orthoester rearrangement and ring-closing metathesis. Coupling of bases via a Pd (0) ...