1-<5'-O-(tert-Butyldimethylsilyl)-2',3'-dideoxy-2'-C-<2''-phenyl-1''-(N-isobutylcarbamoyl)-1''(R)-ethyl>-β-D-ribofuranosyl>uracil

1-((2R,3S,4R,5R)-3-Chloro-4-hydroxy-5-hydroxymethyl-tetrahydro-furan-2-yl)-3-nitro-1H-pyrimidine-2,4-dione

1-(3-iodo-β-D-3-deoxy-xylofuranosyl)-1H-pyrimidine-2,4-dione

1-(5'-O-t-butyldimethylsilyl-2',3'-dideoxy-3'-phenylselenonyl-β-D-glycero-pent-2'-eno-furanosyl)uracil

1-[(2R,3R,4S,5R)-5-(tert-Butyl-dimethyl-silanyloxymethyl)-3-hydroxy-4-phenylselanyl-tetrahydro-furan-2-yl]-1H-pyrimidine-2,4-dione