[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′-O-(2-methoxyethyl)cytidylylidene-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′-O-methylcytidylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′,6′-dideoxy-2′-fluoro-β-D-altrofuranocytidylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′,6′-dideoxy-2′-fluoro-α-L-galactofuranocytidylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-2′-fluoro-β-D-arabino-cytidylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′,6′-dideoxy-2′-fluoro-α-L-talofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-6′-deoxy-2′-O-[2-(methylamino)-2-oxoethyl]-α-L-talofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-6′-deoxy-2′-O-(2-methoxyethyl)-α-L-talofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-6′-deoxy-2′-O-methyl-α-L-talofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′,6′-dideoxy-2′-fluoro-β-D-allofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-6′-deoxy-2′-O-[2-(methylamino)-2-oxoethyl]-β-D-allofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-6′-deoxy-2′-O-(2-methoxyethyl)-β-D-allofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′-O-(2-methoxyethyl)guanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-6′-deoxy-2′-O-methyl-β-D-allofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-2′-fluoroguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′-O-[2-(methylamino)-2-oxoethyl]guanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′-O-methylguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′,6′-dideoxy-2′-fluoro-β-D-altrofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′,6′-dideoxy-2′-fluoro-α-L-galactofuranoguanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-2′-fluoro-β-D-arabino-guanylyl-(3′→5′-7′)-6′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribo-heptofuranothymidine