2',5'-Dideoxy-N-[(1,1-dimethylethoxy)carbonyl]-2',2'-difluoro-5'-iodocytidine

5'-O-[Bis(4-methoxyphenyl)phenylmethyl]-2'-deoxy-2-thiouridine

5-(2-Furanyl)-3-methyluridine

2'-Deoxy-5-(2-thienyl)-4-thiouridine

2'-Deoxy-5-(2-furanyl)-4-thiouridine

5-(2-Thienyl)-4-thiouridine

5-(2-Furanyl)-4-thiouridine

1H-Benzimidazole, 5,6-dibromo-1-[3,5-O-(mercaptophosphinylidene)-β-D-ribofuranosyl]-

5,6-Dichloro-1-[3,5-O-(mercaptophosphinylidene)-β-D-ribofuranosyl]-1H-benzimidazole

1H-Benzimidazole, 1-[3,5-O-(mercaptophosphinylidene)-β-D-ribofuranosyl]-

1'-C-Cyano-2'-deoxyuridine

1-(5-O-1H-Benzimidazol-2-yl-β-D-ribofuranosyl)-5,6-dichloro-1H-benzimidazole

5'-[(Carboxymethyl)sulfonyl]-5'-deoxyuridine

5'-S-(2-Methoxy-2-oxoethyl)-5'-thiouridine

5'-S-(2-Methoxy-2-oxoethyl)-2',3'-O-(1-methylethylidene)-5'-thiouridine

5'-[[(2S)-2-Amino-3-carboxy-1-oxopropyl]amino]-5'-deoxyuridine

5'-S-(Carboxymethyl)-5'-thiouridine

N-(2-Aminoethyl)-2'-deoxy-3',5'-bis-O-[(1,1-dimethylethyl)dimethylsilyl]-5-methylcytidine

N-[2-[[1-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-deoxy-β-D-erythro-pentofuranosyl]-1,2-dihydro-5-methyl-2-oxo-4-pyrimidinyl]amino]ethyl]-2'-deoxy-3',5'-bis-O-[(1,1-dimethylethyl)dimethylsilyl]-5-methylcytidine

N-[2-[[1-[3-O-Acetyl-5-O-[bis(4-methoxyphenyl)phenylmethyl]-2-deoxy-β-D-erythro-pentofuranosyl]-1,2-dihydro-5-methyl-2-oxo-4-pyrimidinyl]amino]ethyl]-2'-deoxy-3',5'-bis-O-[(1,1-dimethylethyl)dimethylsilyl]-5-methylcytidine