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

5-[1-[[4-(Azidomethyl)phenyl]methyl]-1H-1,2,3-triazol-4-yl]-7-(2-deoxy-β-D-erythro-pentofuranosyl)-7H-pyrrolo[2,3-d]pyrimidin-4-amine

N-[7-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-3-O-[[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-2-deoxy-β-D-erythro-pentofuranosyl]-5-[2-[tris(1-methylethyl)silyl]ethynyl]-7H-pyrrolo[2,3-d]pyrimidin-4-yl]-2-methylpropanamide

N-[7-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-deoxy-β-D-erythro-pentofuranosyl]-5-[2-[tris(1-methylethyl)silyl]ethynyl]-7H-pyrrolo[2,3-d]pyrimidin-4-yl]-2-methylpropanamide

N-[7-(2-Deoxy-β-D-erythro-pentofuranosyl)-5-[2-[tris(1-methylethyl)silyl]ethynyl]-7H-pyrrolo[2,3-d]pyrimidin-4-yl]-2-methylpropanamide