1H-Imidazo[2,1-b]purine, 1-[2-deoxy-2-fluoro-3,5-bis-O-(hydroxymercaptophosphinyl)-β-D-ribofuranosyl]-4-[2-(4-nitrophenyl)ethoxy]-, cyclic diester with (1S,2R,3R)-3-(6-amino-9H-purin-9-yl)-1,2-cyclobutanedimethanol

1H-Imidazo[2,1-b]purine, 1-[3-O-[(2-cyanoethoxy)hydroxyphosphinothioyl]-2-deoxy-2-fluoro-5-O-(hydroxymercaptophosphinyl)-β-D-ribofuranosyl]-4-[2-(4-nitrophenyl)ethoxy]-, cyclic diester with (1S,2R,3R)-3-(6-chloro-9H-purin-9-yl)-1,2-cyclobutanedimethanol

1H-Imidazo[2,1-b]purine, 1-[3-O-[[[(1S,2R,3R)-3-(6-chloro-9H-purin-9-yl)-2-(hydroxymethyl)cyclobutyl]methoxy](2-cyanoethoxy)phosphinothioyl]-2-deoxy-2-fluoro-β-D-ribofuranosyl]-4-[2-(4-nitrophenyl)ethoxy]-

1H-Imidazo[2,1-b]purine, 1-[5-O-[bis(4-methoxyphenyl)phenylmethyl]-3-O-[[[(1S,2R,3R)-3-(6-chloro-9H-purin-9-yl)-2-[(triphenylmethoxy)methyl]cyclobutyl]methoxy](2-cyanoethoxy)phosphinothioyl]-2-deoxy-2-fluoro-β-D-ribofuranosyl]-4-[2-(4-nitrophenyl)ethoxy]-

1-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-O-[(S)-[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-2-deoxy-2-fluoro-β-D-ribofuranosyl]-4-[2-(4-nitrophenyl)ethoxy]-1H-imidazo[2,1-b]purine

1-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-O-[(R)-[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-2-deoxy-2-fluoro-β-D-ribofuranosyl]-4-[2-(4-nitrophenyl)ethoxy]-1H-imidazo[2,1-b]purine

1-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-deoxy-2-fluoro-β-D-ribofuranosyl]-4-[2-(4-nitrophenyl)ethoxy]-1H-imidazo[2,1-b]purine

1-(2-Deoxy-2-fluoro-β-D-ribofuranosyl)-4-[2-(4-nitrophenyl)ethoxy]-1H-imidazo[2,1-b]purine

7H-Pyrrolo[2,3-d]pyrimidine, 4-chloro-7-[2-deoxy-2-fluoro-3,5-bis-O-(hydroxymercaptophosphinyl)-β-D-arabinofuranosyl]-, cyclic diester with (1S,2R,3R)-3-(6-chloro-9H-purin-9-yl)-1,2-cyclobutanedimethanol

4-Chloro-7-[3-O-[[[(1S,2R,3R)-3-(6-chloro-9H-purin-9-yl)-2-(hydroxymethyl)cyclobutyl]methoxy](2-cyanoethoxy)phosphinothioyl]-2-deoxy-2-fluoro-β-D-arabinofuranosyl]-7H-pyrrolo[2,3-d]pyrimidine

7-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-O-[[[(1S,2R,3R)-3-(6-chloro-9H-purin-9-yl)-2-[(triphenylmethoxy)methyl]cyclobutyl]methoxy](2-cyanoethoxy)phosphinothioyl]-2-deoxy-2-fluoro-β-D-arabinofuranosyl]-4-chloro-7H-pyrrolo[2,3-d]pyrimidine

7-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-O-[[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-2-deoxy-2-fluoro-β-D-arabinofuranosyl]-4-chloro-7H-pyrrolo[2,3-d]pyrimidine

7-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-deoxy-2-fluoro-β-D-arabinofuranosyl]-4-chloro-7H-pyrrolo[2,3-d]pyrimidine

7H-Pyrrolo[2,3-d]pyrimidine, 4-chloro-7-[3-O-[(2-cyanoethoxy)hydroxyphosphinothioyl]-2-deoxy-5-O-(hydroxymercaptophosphinyl)-β-D-erythro-pentofuranosyl]-, cyclic diester with (1S,2R,3R)-3-(6-chloro-9H-purin-9-yl)-1,2-cyclobutanedimethanol

7H-Pyrrolo[2,3-d]pyrimidine, 4-chloro-7-[3-O-[[[(1S,2R,3R)-3-(6-chloro-9H-purin-9-yl)-2-(hydroxymethyl)cyclobutyl]methoxy](2-cyanoethoxy)phosphinothioyl]-2-deoxy-β-D-erythro-pentofuranosyl]-

7-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-O-[[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-2-deoxy-β-D-erythro-pentofuranosyl]-4-chloro-7H-pyrrolo[2,3-d]pyrimidine