1,2-Cyclopentanediol, 3-(6-amino-9H-purin-9-yl)-5-(hydroxymethyl)-, (1R,2R,3R,5R) 62357-70-4 AIDS-001018 AIDS001018 C-2',3'-OH ara-A Carbocyclic-2',3'-OH ara-adenosine NSC615828 ara-A araA