(4S,2R,3R,5R)-2-[6-Chloro-2-(3-fluoroprop-1-ynyl)purin-9-yl]-5-(hydroxymethyl)oxolane-3,4-diol 2-(3-Fluoropropyn-1-yl)-6-chloro-9-(.beta.-D-ribofuranosyl)purine AIDS-167858 AIDS167858