2-((N-(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)carbamoyl)amino)phenyl acetate AIDS-057975 AIDS057975