Compounds of the formula I:including any possible stereoisomers thereof, wherein:R4is a monophosphate, diphosphate or triphosphate ester or R4 isR7is optionally substituted phenyl, optionally substituted naphthyl, or optionally substituted indolylR8 and R8are hydrogen, C1-C6alkyl, benzyl, or phenyl or R8 and R8 form C3-C7cycloalkylR9is C1-C10alkyl, C3-C7cycloalkyl, phenyl or phenyl-C1-C6alkyl, wherein the phenyl moiety in phenyl or phenyl-C1-C6alkyl is optionally substitutedor a pharmaceutically acceptable salt or solvate thereofpharmaceutical formulations and the use of compounds I as HCV inhibitors.
