(4S,2R,3R,5R)-2-[2-((1Z)-2-Fluorovinyl)-6-chloropurin-9-yl]-5-(hydroxymethyl)oxolane-3,4-diol (Z)-2-(2-Fluorovinyl)-6-chloro-9-(.beta.-D-ribofuranosyl) purine AIDS-167860 AIDS167860