AIDS-153577 AIDS153577 Methyl 2-{(2S,4R,5R)-5-(2,4-dioxo(1,3-dihydropyrimidinyl))-4-hydroxy-2-[(1,1,2,2-tetramethyl-1-silapropoxy)methyl]-3-2,4,5-trihydrofurylidene}acetate NSC700836