3-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-O-[[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-2-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribofuranosyl]-3,5-dihydro-5-[2-(4-nitrophenyl)ethyl]-9H-imidazo[1,2-a]purin-9-one

3-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribofuranosyl]-3,5-dihydro-5-[2-(4-nitrophenyl)ethyl]-9H-imidazo[1,2-a]purin-9-one

3-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-β-D-ribofuranosyl]-3,5-dihydro-5-[2-(4-nitrophenyl)ethyl]-9H-imidazo[1,2-a]purin-9-one

3,5-Dihydro-5-[2-(4-nitrophenyl)ethyl]-3-β-D-ribofuranosyl-9H-imidazo[1,2-a]purin-9-one

3,5-Dihydro-5-[2-(4-nitrophenyl)ethyl]-3-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-9H-imidazo[1,2-a]purin-9-one

3,4-Dihydro-3-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-9H-imidazo[1,2-a]purin-9-one