[(2R,3R,4R,5R)-4-(tert-Butyl-dimethyl-silanyloxy)-2-(tert-butyl-dimethyl-silanyloxymethyl)-5-(2,4-dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-3-hydroxy-tetrahydro-furan-3-yl]-acetonitrile

1-[2,5-di-O-(tert-butyldimethylsilyl)-3-C-(cyanomethyl)-β-D-ribo-pentofuranosyl]cytosine

1-[2,5-di-O-(tert-butyldimethylsilyl)-3-C-(carbamoylmethyl)-β-D-ribo-pentofuranosyl]cytosine

1-[2,5-di-O-(tert-butyldimethylsilyl)-3-C-(N-methylcarbamoylmethyl)-β-D-ribo-pentofuranosyl]cytosine

1-[2,5-di-O-(tert-butyldimethylsilyl)-3-C-(N,N'-dimethylcarbamoylmethyl)-β-D-ribo-pentofuranosyl]uracil