(+)-1-[(1S,4R)-2,3-dideoxy-2,3-didehydro-2-fluoro-4-thio-beta-L-ribofuranosyl]-5-fluorocytosine 4-Amino-5-fluoro-1-(3-fluoro-5-hydroxymethyl-2,5-dihydro-thiophen-2-yl)-1H-pyrimidin-2-one AIDS-163227 AIDS163227