1-[(2S,3S,5R)-3-[[[Bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]oxy]-5-[1,6-dihydro-2-[(2-methyl-1-oxopropyl)amino]-6-oxo-9H-purin-9-yl]tetrahydro-2-furanyl]cyclopropyl 4-oxopentanoate

1-[(2S,3S,5R)-5-[1,6-Dihydro-2-[(2-methyl-1-oxopropyl)amino]-6-oxo-9H-purin-9-yl]tetrahydro-3-hydroxy-2-furanyl]cyclopropyl 4-oxopentanoate

1-[(2S,3S,5R)-5-[1,6-Dihydro-2-[(2-methyl-1-oxopropyl)amino]-6-oxo-9H-purin-9-yl]-3-[[(1,1-dimethylethyl)dimethylsilyl]oxy]tetrahydro-2-furanyl]cyclopropyl 4-oxopentanoate

N-[9-[(2R,4S,5S)-4-[[(1,1-Dimethylethyl)dimethylsilyl]oxy]tetrahydro-5-(1-hydroxycyclopropyl)-2-furanyl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-2-methylpropanamide

N-[9-[(2R,4S,5S)-Tetrahydro-4-hydroxy-5-[1-[(4-methoxyphenyl)diphenylmethoxy]cyclopropyl]-2-furanyl]-9H-purin-6-yl]benzamide

N-[9-[(2R,4S,5S)-4-[[(1,1-Dimethylethyl)dimethylsilyl]oxy]tetrahydro-5-[1-[(4-methoxyphenyl)diphenylmethoxy]cyclopropyl]-2-furanyl]-9H-purin-6-yl]benzamide

N-[9-[(2R,4S,5S)-4-[[(1,1-Dimethylethyl)dimethylsilyl]oxy]tetrahydro-5-(1-hydroxycyclopropyl)-2-furanyl]-9H-purin-6-yl]benzamide