1-(3-Amino-2,3,6-trideoxy-.alpha.-L-ribo-hexofuranosyl)thymine 2,4(1H,3H)-Pyrimidinedione, 1-(3-amino-2,3,6-trideoxy-.alpha.-L-ribo-hexofuranosyl)-5-methyl- AIDS-002985 AIDS002985 Amino nucleoside