Patent ID: 8431588

Claim:
A compound of formula I: including any possible stereoisomers thereof, wherein: R 2 is hydrogen or C 1 -C 4 alkyl; R 3 and R 4 are independently selected from the group consisting of hydrogen, —C(═O)R 5 , and —C(═O)CHR 6 —NH 2 ; or R 3 is hydrogen and R 4 is a monophosphate-, diphosphate-, or triphosphate ester; or R 3 is hydrogen, —C(═O)CHR 5 , or —C(═O)CHR 6 —NH 2 and R 4 is a group of formula each R 5 is independently selected from the group consisting of hydrogen, C 1 -C 6 alkyl, and C 3 -C 7 cycloalkyl; R 6 is hydrogen or C 1 -C 6 alkyl; R 7 is phenyl, optionally substituted with 1, 2 or 3 substituents each independently selected from halo, C 1 -C 6 alkyl, C 3 -C 6 alkenyl, C 1 -C 6 alkoxy, hydroxy, and amino, or R 7 is naphthyl; or R 7 is indolyl; R 8 is hydrogen, C 1 -C 6 alkyl, benzyl; R 8 is hydrogen, C 1 -C 6 alkyl, benzyl; or R 8 and R 8′ together with the carbon atom to which they are attached form C 3 -C 7 cycloalkyl; R 9 is C 1 -C 6 alkyl, benzyl, or phenyl, wherein said phenyl may be optionally substituted with 1, 2 or 3 substituents each independently selected from hydroxy, C 1 -C 6 alkoxy, amino, mono- and diC 1 -C 6 alkylamino; provided that R 2 , R 3 and R 4 are not all hydrogen; or a pharmaceutically acceptable salt thereof.