2',3'-Didehydro-2',3'-dideoxytriciribine 2',3'-d4TCN 6-Amino-8-(2,3-dideoxy-2,3-dihydro-.beta.-D-ribofuranosyl)-4-methylpyrrolo[4,3,2-de]pyrimido[4,5-c]pyridazine AIDS-115811 AIDS115811