(Z)-2-(2-Fluorovinyl)-9-(.beta.-D-ribofuranosyl)hypoxanthine 9-[(4S,2R,3R,5R)-3,4-Dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-2-((1Z)-2-fluorovinyl)hydropurin-6-one AIDS-167865 AIDS167865