N′-[2-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-O-[[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-2-deoxy-β-D-erythro-pentofuranosyl]-6,7-dihydro-7-oxo-2H-pyrazolo[4,3-d]pyrimidin-5-yl]-N,N-dimethylmethanimidamide

N′-[2-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-deoxy-β-D-erythro-pentofuranosyl]-6,7-dihydro-7-oxo-2H-pyrazolo[4,3-d]pyrimidin-5-yl]-N,N-dimethylmethanimidamide

N′-[2-(2-Deoxy-β-D-erythro-pentofuranosyl)-6,7-dihydro-7-oxo-2H-pyrazolo[4,3-d]pyrimidin-5-yl]-N,N-dimethylmethanimidamide

5-Amino-2-(2-deoxy-β-D-erythro-pentofuranosyl)-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

Ethyl 4-amino-1-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-1H-pyrazole-3-carboxylate

5-Amino-2,6-dihydro-2-β-D-ribofuranosyl-7H-pyrazolo[4,3-d]pyrimidin-7-one