4-Amino-8-{3-[6-(3-{9-amino-3,6-dioxa-7,7-dioxo-1-(1,1,2,2-tetramethyl-1-silapropoxy)-4-[(1,1,2,2-tetramethyl-1-silapropoxy)methyl]-7-thiaspiro[4.4]non-8-en-2-yl}-5-methyl-2,6-dioxo(1,3-dihydropyrimidinyl))hexa-2,4-diynyl]-5-methyl-2,4-dioxo(1,3-dihydropyrimidinyl)}-6,9-bis(1,1,2,2-tetramethyl-1-silapropoxy)-1,7-dioxa-2-thiaspiro[4.4]non-3-ene-2,2-dione AIDS-122979 AIDS122979