N-[5-Fluoro-1-((2R,5S)-3-fluoro-5-hydroxymethyl-2,5-dihydro-thiophen-2-yl)-2-oxo-1,2-dihydro-pyrimidin-4-yl]-benzamide

1-[5-O-(tert-butyldiphenylsilyl)-2,3-dideoxy-2,3-didehydro-2-fluoro-4-thio-β-D-ribofuranosyl]thymine

N4-benzoyl-1-[5-O-(tert-butyldiphenylsilyl)-2,3-dideoxy-2,3-didehydro-2-fluoro-4-thio-β-D-ribofuranosyl]cytosine

1-[(1R,2R,4S)-5-O-(tert-butyldiphenylsilyl)-2,3-dideoxy-2-fluoro-2-phenylselanyl-4-thio-β-D-pentofuranosyl]uracil

N4-benzoyl-1-[5-O-(tert-butyldiphenylsilyl)-2,3-dideoxy-2,3-didehydro-2-fluoro-4-thio-β-D-ribofuranosyl]-5-fluorocytosine