Uridine, [P(S)]-N-acetyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-[(1,3-dimethyl-2-imidazolidinylidene)amino]-2′-O-methylcytidylyl-(3′→5′)-2′-deoxy-2′-fluoro-

Uridine, [P(R)]-N-acetyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-[(1,3-dimethyl-2-imidazolidinylidene)amino]-2′-O-methylcytidylyl-(3′→5′)-2′-deoxy-2′-fluoro-3′-O-[(1S,3S,3aS)-tetrahydro-3-[(methyldiphenylsilyl)methyl]-1H,3H-pyrrolo[1,2-c][1,3,2]oxazaphosphol-1-yl]-

Uridine, [P(R)]-N-acetyl-5′-O-[bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-[(1,3-dimethyl-2-imidazolidinylidene)amino]-2′-O-methylcytidylyl-(3′→5′)-2′-deoxy-2′-fluoro-

[P(S)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-[(1,3-dimethyl-2-imidazolidinylidene)amino]-2′-O-methyluridylyl-(3′→5′)-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-2′-fluorouridine

[P(R)]-5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-[(1,3-dimethyl-2-imidazolidinylidene)amino]-2′-O-methyluridylyl-(3′→5′)-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-2′-fluorouridine

5′-O-[Bis(4-methoxyphenyl)phenylmethyl]-P-deoxy-P-[(1,3-dimethyl-2-imidazolidinylidene)amino]-2′-O-methyluridylyl-(3′→5′)-2′-deoxy-3′-O-[(1,1-dimethylethyl)dimethylsilyl]-2′-fluorouridine

2-(3,4-Dimethoxyphenyl)ethyl (6R)-17-[2,3:5,6-bis-O-(1-methylethylidene)-β-D-gulofuranosyl]-15-oxo-7,14,16-trioxa-2,17-diazatrispiro[3.1.1.5.2.2]heptadecane-2-carboxylate

(3S,5R)-2-[2,3:5,6-Bis-O-(1-methylethylidene)-β-D-gulofuranosyl]-3-[(4-hydroxyphenyl)methyl]-1,6,13-trioxa-2-azadispiro[4.1.5.2]tetradecan-14-one

(3R,5R)-2-[2,3:5,6-Bis-O-(1-methylethylidene)-β-D-gulofuranosyl]-3-[4-(4-pyridinyl)phenyl]-1,6,13-trioxa-2-azadispiro[4.1.5.2]tetradecan-14-one