6H-Purin-6-one, 2-amino-1,9-dihydro-9-[(2-hydroxyethoxy)methyl]- and 2,4(1H,3H)-Pyrimidinedione, 1-[(2R,4S,5R)-5-ethynyltetrahydro-4-hydroxy-2-furanyl]-5-methyl- AIDS-196042 AIDS196042