AIDS-148488 AIDS148488 Methyl 2,2,4,4-tetraisopropyl-11-oxo-6,6a,13a,13b-tetrahydro-7aH,11H-[1,3,5,2,4]trioxadisilocino[6'',7'':4',5']furo[2',3':4,5][1,3]oxazolo[3,2-a]pyrimidine-7a-carboxylate NSC680838