2-Amino-9-[(2R,3R,3aS,7aS,9R,10R,10aS,14aS)-9-(6-amino-9H-purin-9-yl)dodecahydro-3,5,10,12-tetrahydroxy-5,12-dioxido-2H,7H-difuro[3,2-d:3′,2′-j][1,7,3,9,2,8]dioxadiazadiphosphacyclododecin-2-yl]-1,9-dihydro-6H-purin-6-one

5'-Amino-N-benzoyl-2',5'-dideoxy-2'-fluoroadenosine

5'-Azido-N-benzoyl-2',5'-dideoxy-2'-fluoroadenosine

N-Benzoyl-2',5'-dideoxy-2'-fluoro-5'-iodoadenosine

N-Benzoyl-2′,5′-dideoxy-2′-fluoro-5′-[(triphenylmethyl)amino]adenosine

5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-2′-O-[(1,1-dimethylethyl)dimethylsilyl]-N-(2-methyl-1-oxopropyl)-3′-[(phenylmethylene)amino]guanosine

5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-2′-O-[(1,1-dimethylethyl)dimethylsilyl]-3′-[(phenylmethylene)amino]guanosine

[N(E)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-N-[(dimethylamino)methylene]-2′-O-[(1,1-dimethylethyl)dimethylsilyl]-3′-[(phenylmethylene)amino]guanosine

[N(E)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-N-[(dimethylamino)methylene]-2′-O-[(1,1-dimethylethyl)dimethylsilyl]-3′-[(phenylmethyl)amino]guanosine

5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-2′-O-[(1,1-dimethylethyl)dimethylsilyl]-3′-[(phenylmethyl)amino]guanosine

5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-3′-[(phenylmethyl)amino]guanosine

(1E)-N′-[9-[(3aR,4S,6R,6aR)-4-[[Bis(4-methoxyphenyl)phenylmethoxy]methyl]hexahydro-2-oxo-3-(phenylmethyl)furo[3,4-d]oxazol-6-yl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-N,N-dimethylmethanimidamide

(1E)-N′-[9-[(3aR,4S,6R,6aR)-Hexahydro-4-(hydroxymethyl)-2-oxo-3-(phenylmethyl)furo[3,4-d]oxazol-6-yl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-N,N-dimethylmethanimidamide

(1E)-N′-[9-[(3aR,4S,6R,6aR)-4-[[[(1,1-Dimethylethyl)diphenylsilyl]oxy]methyl]hexahydro-2-oxo-3-(phenylmethyl)furo[3,4-d]oxazol-6-yl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-N,N-dimethylmethanimidamide

(1E)-N′-[9-[3-Bromo-3-deoxy-5-O-[(1,1-dimethylethyl)diphenylsilyl]-2-O-[[(phenylmethyl)amino]carbonyl]-β-D-xylofuranosyl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-N,N-dimethylmethanimidamide

(1E)-N′-[9-[3-Bromo-3-deoxy-5-O-[(1,1-dimethylethyl)diphenylsilyl]-β-D-xylofuranosyl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-N,N-dimethylmethanimidamide

(1E)-N′-[9-[2-O-Acetyl-3-bromo-3-deoxy-5-O-[(1,1-dimethylethyl)diphenylsilyl]-β-D-xylofuranosyl]-6,9-dihydro-6-oxo-1H-purin-2-yl]-N,N-dimethylmethanimidamide

[N(E)]-N-[(Dimethylamino)methylene]-5′-O-[(1,1-dimethylethyl)diphenylsilyl]guanosine

3′-Amino-3′-deoxy-2′-O-[(1,1-dimethylethyl)dimethylsilyl]-N-(2-methyl-1-oxopropyl)guanosine

N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-2′-O-[(1,1-dimethylethyl)dimethylsilyl]-3′-[(Z)-(phenylmethylene)amino]adenosine