Pentyl 3-[(2R)-2-chloro-2-deoxy-2-methyl-5-O-[(S)-[[(1R)-1-methyl-2-(1-methylethoxy)-2-oxoethyl]amino]phenoxyphosphinyl]-β-D-erythro-pentofuranosyl]-3,6-dihydro-2,6-dioxo-1(2H)-pyrimidinecarboxylate

N-[[P(S),2′R]-2′-Chloro-2′-deoxy-3-[1-[(ethoxycarbonyl)oxy]ethyl]-2′-methyl-P-phenyl-5′-uridylyl]-D-alanine 1-methylethyl ester

N-[[P(S),2′R]-2′-Deoxy-3-[1-[(ethoxycarbonyl)oxy]ethyl]-2′-fluoro-2′-methyl-P-phenyl-5′-uridylyl]-D-alanine 1-methylethyl ester

N-[[P(S),2′R]-2′-Deoxy-4-O-(2,2-dimethyl-1-oxopropyl)-2′-fluoro-2′-methyl-P-thio-5′-uridylyl]-L-alanine 1-methylethyl ester

N-[[P(S),2′R]-3-[(Acetyloxy)methyl]-2′-deoxy-2′-fluoro-2′-methyl-P-phenyl-5′-uridylyl]-L-alanine 1-methylethyl ester

N-[[P(S),2′R]-2′-Deoxy-2′-fluoro-2′-methyl-4-O-[(pentyloxy)carbonyl]-P-phenyl-5′-uridylyl]-L-alanine 1-methylethyl ester

N-[[P(S),2′R]-2′-Deoxy-4-O-[1-[(ethoxycarbonyl)oxy]ethyl]-2′-fluoro-2′-methyl-P-phenyl-5′-uridylyl]-L-alanine 1-methylethyl ester

Pentyl 3-[(2R)-2-deoxy-2-fluoro-2-methyl-5-O-[(S)-[[(1S)-1-methyl-2-(1-methylethoxy)-2-oxoethyl]amino]phenoxyphosphinyl]-β-D-erythro-pentofuranosyl]-3,6-dihydro-2,6-dioxo-1(2H)-pyrimidinecarboxylate

N-[[P(S),2′R]-2′-Deoxy-3-[1-[(ethoxycarbonyl)oxy]ethyl]-2′-fluoro-2′-methyl-P-phenyl-5′-uridylyl]-L-alanine 1-methylethyl ester

Uridine, 4-O-[1-[[(cyclohexyloxy)carbonyl]oxy]ethyl]-2′-C-methyl-, 5′-[2-[(3-hydroxy-2,2-dimethyl-1-oxopropyl)thio]ethyl [P(S)]-N-(phenylmethyl)phosphoramidate]

Uridine, 3-[1-[[(cyclohexyloxy)carbonyl]oxy]ethyl]-2′-C-methyl-, 5′-[2-[(3-hydroxy-2,2-dimethyl-1-oxopropyl)thio]ethyl [P(S)]-N-(phenylmethyl)phosphoramidate]

Uridine, 3-[1-(acetyloxy)ethyl]-2′-C-methyl-, 5′-[2-[(3-hydroxy-2,2-dimethyl-1-oxopropyl)thio]ethyl [P(S)]-N-(phenylmethyl)phosphoramidate]

Uridine, 3-[1-(acetyloxy)ethyl]-2′-deoxy-2′-fluoro-2′-methyl-, 5′-[2-[(3-hydroxy-2,2-dimethyl-1-oxopropyl)thio]ethyl [P(S)]-N-(phenylmethyl)phosphoramidate], (2′R)-

Uridine, 3-[1-(acetyloxy)ethyl]-2′-chloro-2′-deoxy-2′-methyl-, 5′-[2-[(3-hydroxy-2,2-dimethyl-1-oxopropyl)thio]ethyl [P(S)]-N-(phenylmethyl)phosphoramidate], (2′R)-

N-[[P(S),2′R]-2′-Chloro-4-O-[1-[[(cyclohexyloxy)carbonyl]oxy]ethyl]-2′-deoxy-2′-methyl-P-phenyl-5′-uridylyl]-D-alanine 1-methylethyl ester

N-[[P(S),2′R]-2′-Chloro-3-[1-[[(cyclohexyloxy)carbonyl]oxy]ethyl]-2′-deoxy-2′-methyl-P-phenyl-5′-uridylyl]-D-alanine 1-methylethyl ester

N-[[P(S),2′R]-3-[1-(Acetyloxy)ethyl]-2′-chloro-2′-deoxy-2′-methyl-P-phenyl-5′-uridylyl]-D-alanine 1-methylethyl ester

N-[[P(S),2′R]-4-O-[(Acetyloxy)methyl]-2′-deoxy-2′-fluoro-2′-methyl-P-phenyl-5′-uridylyl]-L-alanine 1-methylethyl ester

N-[[P(S),2′R]-3-[1-[[(Cyclohexyloxy)carbonyl]oxy]ethyl]-2′-deoxy-2′-fluoro-2′-methyl-P-phenyl-5′-uridylyl]-L-alanine 1-methylethyl ester

N-[[P(S),2′R]-3-[1-(Acetyloxy)ethyl]-2′-deoxy-2′-fluoro-2′-methyl-P-phenyl-5′-uridylyl]-L-alanine 1-methylethyl ester