AIDS-105021 AIDS105021 {1-[9-Amino-1,4-bis(1,1,2,2-tetramethyl-1-silapropoxy)-7,7-dioxo-3,6-dioxa-7-thiaspiro[4.4]non-8-en-2-yl]-2-oxohydropyrimidin-4-yl}amino acetate