2-{(2S,4R,5R)-5-(5-Methyl-2,4-dioxo(1,3-dihydropyrimidinyl))-4-(1,1,2,2-tetramethyl-1-silapropoxy)-2-[(1,1,2,2-tetramethyl-1-silapropoxy)methyl]-3-2,4,5-trihydrofurylidene}ethanenitrile AIDS-149789 AIDS149789 NSC685189