3'-O-(2-Cyanoethyl)-2'-deoxy-5-iodouridine

5-Methyl-2'-O-methyl-2-thiouridine

5-Methyl-2'-O-propyl-2-thiouridine

2',3'-Dideoxy-2'-fluorouridine

2'-Deoxy-5'-O-[(1,1-dimethylethyl)dimethylsilyl]-2'-fluorouridine

2',3'-Dideoxy-5-fluoro-3'-iodouridine

3'-Chloro-2',3'-dideoxy-5-fluorouridine

3'-Bromo-2',3'-dideoxy-5-fluorouridine

2-[4-(5,5-Dimethyl-1,3,2-dioxaborinan-2-yl)phenyl]-2',3',5'-tris-O-[(1,1-dimethylethyl)dimethylsilyl]-6-O-methylinosine

N-[1-[Bis(1-methylethyl)amino]ethylidene]-5'-deoxy-5-fluorocytidine

5'-Deoxy-N-[1-(dibutylamino)ethylidene]-5-fluorocytidine

5'-Deoxy-N-[1-(diethylamino)ethylidene]-5-fluorocytidine

5'-Deoxy-N-[1-(dimethylamino)ethylidene]-5-fluorocytidine

4'-C-Azidocytidine 3',5'-bis(2-methylpropanoate)

4'-C-Azidocytidine 2',5'-bis(2-methylpropanoate)

Glycine, N-[(1,1-dimethylethoxy)carbonyl]-, 5'-ester with 3'-O-[(4-chlorophenyl)methyl]-2'-deoxy-5-fluorouridine

5'-O-[Bis(4-methoxyphenyl)phenylmethyl]-3'-O-[(1,1-dimethylethyl)dimethylsilyl]-2'-O-(2-methoxyethyl)-5-methyluridine

3'-O-[(1,1-Dimethylethyl)dimethylsilyl]-2'-O-(2-methoxyethyl)-5-methyl-5'-thiouridine

5'-[[Bis(2-cyanoethoxy)phosphinyl]amino]-5'-deoxy-2'-O-(2-methoxyethyl)-5-methyluridine

5'-Amino-5'-deoxy-3'-O-[(1,1-dimethylethyl)dimethylsilyl]-2'-O-(2-methoxyethyl)-5-methyluridine