Novel 3′-deoxy analogs of the anti-HBV agent entecavir: synthesis of enantiomers from a single chiral epoxide

A synthesis of novel 3′-deoxy analogs of the anti-HBV agent entecavir (BMS-200475) was devised using regioselective ring opening of suitable cyclopentene epoxides as the key step. This versatile approach afforded access to an enantiomeric pair of carbocyclic nucleosides from a single chiral intermediate.