Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-3′-O-[(2R,3aS,7aS)-hexahydro-3-methyl-1,3,2-benzoxazaphosphol-2(3H)-yl]-N-(2-methyl-1-oxopropyl)-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1R,3R,3aS)-tetrahydro-3-(4-methoxyphenyl)-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1′S,3′aS,4′S,7′R)-tetrahydrospiro[cyclopentane-1,3′(3′aH)-[4,7]methano[1H][1,3,2]oxazaphospholo[3,4-a]pyridin]-1′-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1′S,3′aS)-tetrahydro-5′,5′-dimethylspiro[cyclopentane-1,3′-[1H,3H]pyrrolo[1,2-c][1,3,2]oxazaphosphol]-1′-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1S,3R,3aS)-tetrahydro-3-(4-methoxyphenyl)-3-methyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1S,3R,3aS)-tetrahydro-3-methyl-3-(phenylmethyl)-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Cytidine, N-acetyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-3′-O-[(1R,3R,3aS)-tetrahydro-3-(phenylmethyl)-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Adenosine, N-benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-3′-O-[(1S,3S,3aS,4aS,7aS)-octahydro-3-[(methyldiphenylsilyl)methyl]-1H-cyclopenta[4,5]pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(2R,4S,5S)-4-methyl-4-phenyl-3-oxa-1-aza-2-phosphabicyclo[3.2.0]hept-2-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(2S,4S,5S)-4-methyl-4-phenyl-3-oxa-1-aza-2-phosphabicyclo[3.2.0]hept-2-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(2S,4R,5S)-4-methyl-4-phenyl-3-oxa-1-aza-2-phosphabicyclo[3.2.0]hept-2-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(2R,4R,5S)-4-phenyl-3-oxa-1-aza-2-phosphabicyclo[3.2.0]hept-2-yl]-

Cytidine, N-benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-3′-O-[(1S,3S,3aS,4aS,8aS)-octahydro-3-[(methyldiphenylsilyl)methyl]-1H,3H-[1,3,2]oxazaphospholo[3,4-a]indol-1-yl]-

Cytidine, N-benzoyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-3′-O-[(3S,3aS)-tetrahydro-5,5-dimethyl-3-[(methyldiphenylsilyl)methyl]-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1′S,3′aS,4′aS,8′aS)-octahydrospiro[cyclopentane-1,3′-[1H,3H][1,3,2]oxazaphospholo[3,4-a]indol]-1′-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1S,3R,3aS,4aS,8aS)-octahydro-3-methyl-3-phenyl-1H,3H-[1,3,2]oxazaphospholo[3,4-a]indol-1-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-3′-O-[(2S,4S)-3,4-bis(1-methylethyl)-1-oxa-3-aza-2-phosphaspiro[4.4]non-2-yl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1S,3aS)-tetrahydro-3,3-diphenyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-N-(2-methyl-1-oxopropyl)-3′-O-[(1S,3aS)-tetrahydro-3,3-dimethyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Cytidine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-2′-deoxy-3′-O-[(1S,3R,3aS)-3-(3,5-difluorophenyl)tetrahydro-3-methyl-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-N-(2-methyl-1-oxopropyl)-