Guanosine, 3′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-5′-O-[[hydroxy[(4-methoxy-1-oxido-2-pyridinyl)methoxy]phosphinyl]methyl]-N-(2-methyl-1-oxopropyl)-6-O-[2-[(4-nitrophenyl)thio]ethyl]-

Guanosine, 3′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-5′-O-[[hydroxy[(4-methoxy-1-oxido-2-pyridinyl)methoxy]phosphinyl]methyl]-N-(2-methyl-1-oxopropyl)-6-O-[2-(4-nitrophenyl)ethyl]-

Adenosine, N-benzoyl-3′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-5′-O-[[hydroxy[(4-methoxy-1-oxido-2-pyridinyl)methoxy]phosphinyl]methyl]-

Cytidine, N-benzoyl-3′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-5′-O-[[hydroxy[(4-methoxy-1-oxido-2-pyridinyl)methoxy]phosphinyl]methyl]-

Thymidine, 3′-O-[bis(4-methoxyphenyl)phenylmethyl]-5′-O-[[hydroxy[(4-methoxy-1-oxido-2-pyridinyl)methoxy]phosphinyl]methyl]-4-O-[2-[(4-nitrophenyl)thio]ethyl]-

Thymidine, 3′-O-[bis(4-methoxyphenyl)phenylmethyl]-5′-O-[[hydroxy[(4-methoxy-1-oxido-2-pyridinyl)methoxy]phosphinyl]methyl]-

1-[2-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-deoxy-5-O-[(hydroxymethoxyphosphinyl)methyl]-β-D-threo-pentofuranosyl]-5-methyl-2,4(1H,3H)-pyrimidinedione

1-[2-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-deoxy-β-D-threo-pentofuranosyl]-5-methyl-2,4(1H,3H)-pyrimidinedione

1-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-deoxy-2-O-[(hydroxymethoxyphosphinyl)methyl]-β-D-threo-pentofuranosyl]-5-methyl-2,4(1H,3H)-pyrimidinedione

Uridine, 2′-O-[bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-5′-O-[(hydroxymethoxyphosphinyl)methyl]-5-methyl-

Uridine, 2′-O-[bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-5-methyl-

Uridine, 2′-O-[bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-5-methyl-, 5′-(methyl carbonate)

Uridine, 3′-deoxy-5-methyl-, 5′-(methyl carbonate)

Uridine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-2′-O-[(hydroxymethoxyphosphinyl)methyl]-5-methyl-

Uridine, 3′-deoxy-5-methyl-, 2′-acetate 5′-(methyl carbonate)

1-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-deoxy-3-O-[(hydroxymethoxyphosphinyl)methyl]-β-D-threo-pentofuranosyl]-5-methyl-2,4(1H,3H)-pyrimidinedione

1-[3-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-deoxy-5-O-[(hydroxymethoxyphosphinyl)methyl]-β-D-threo-pentofuranosyl]-5-methyl-2,4(1H,3H)-pyrimidinedione

5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-3′-O-[(hydroxymethoxyphosphinyl)methyl]thymidine

3′-O-[Bis(4-methoxyphenyl)phenylmethyl]-5′-O-[(hydroxymethoxyphosphinyl)methyl]thymidine

Uridine, 2′-O-(4-methoxy-2,2,6,6-tetramethyl-1-piperidinyl)-5-methyl-