[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-methylthymidylyl-(3′→5′)-N-benzoyl-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]cytidine

[P(S)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methyl-N-(2-methyl-1-oxopropyl)guanylyl-(3′→5′)-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-N-(2-methyl-1-oxopropyl)guanosine

[P(S)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methyl-N-(2-methyl-1-oxopropyl)guanylyl-(3′→5′)-N-benzoyl-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]cytidine

[P(S)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methyl-N-(2-methyl-1-oxopropyl)guanylyl-(3′→5′)-N-benzoyl-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]adenosine

[P(S)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methyl-N-(2-methyl-1-oxopropyl)guanylyl-(3′→5′)-3′-O-[(1,1-dimethylethyl)dimethylsilyl]thymidine

[P(S)]-N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methylcytidylyl-(3′→5′)-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-N-(2-methyl-1-oxopropyl)guanosine

[P(S)]-N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methylcytidylyl-(3′→5′)-N-benzoyl-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]cytidine

[P(S)]-N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methylcytidylyl-(3′→5′)-N-benzoyl-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]adenosine

[P(S)]-N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methyladenylyl-(3′→5′)-3′-O-[(1,1-dimethylethyl)dimethylsilyl]thymidine

[P(S)]-N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methyladenylyl-(3′→5′)-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-N-(2-methyl-1-oxopropyl)guanosine

[P(S)]-N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P,2′-dideoxy-P-methyladenylyl-(3′→5′)-N-benzoyl-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]cytidine

[P(S)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-methylthymidylyl-(3′→5′)-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-N-(2-methyl-1-oxopropyl)guanosine

[P(S)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-methylthymidylyl-(3′→5′)-N-benzoyl-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]cytidine

[P(R)]-N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P-(2-cyanoethyl)-P-deoxo-2′-deoxyadenylyl-(3′→5′)-3′-O-[(1,1-dimethylethyl)dimethylsilyl]thymidine

[P(S)]-N-Benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P-(2-cyanoethyl)-P-deoxo-2′-deoxyadenylyl-(3′→5′)-3′-O-[(1,1-dimethylethyl)dimethylsilyl]thymidine

[P(S)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P-(2-cyanoethyl)-P-deoxo-2′-deoxy-N-(2-methyl-1-oxopropyl)guanylyl-(3′→5′)-3′-O-[(1,1-dimethylethyl)dimethylsilyl]thymidine