N-[7-[3-O-[(1,1-Dimethylethyl)dimethylsilyl]-2-O-(hydroxyphosphinyl)-β-D-ribofuranosyl]-4,7-dihydro-4-oxo-3H-pyrrolo[2,3-d]pyrimidin-2-yl]-2-methylpropanamide

N-[1-[3-O-[(1,1-Dimethylethyl)dimethylsilyl]-2-O-(hydroxyphosphinyl)-β-D-ribofuranosyl]-4,5-dihydro-4-oxo-1H-pyrazolo[3,4-d]pyrimidin-6-yl]-2-methylpropanamide

N-[1-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-O-[[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-3-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribofuranosyl]-4,5-dihydro-4-oxo-1H-pyrazolo[3,4-d]pyrimidin-6-yl]-2-methylpropanamide

N-[7-[5-O-[Bis(4-methoxyphenyl)phenylmethyl]-2-O-[[bis(1-methylethyl)amino](2-cyanoethoxy)phosphino]-3-O-[(1,1-dimethylethyl)dimethylsilyl]-β-D-ribofuranosyl]-4,7-dihydro-4-oxo-3H-pyrrolo[2,3-d]pyrimidin-2-yl]-2-methylpropanamide

Guanosine, 5′-O-[bis(4-methoxyphenyl)phenylmethyl]-3′-deoxy-N-(2-methyl-1-oxopropyl)-, 2′-[P-methyl-N,N-bis(1-methylethyl)phosphonamidite]