1-[9-{[tert-butyl(dimethyl)silyl]oxy}-6-({[tert-butyl(dimethyl)silyl]oxy}methyl)-2-oxo-1,7-dioxaspiro[4.4]non-8-yl]pyrimidine-2,4(1H,3H)-dione 2,4(1H,3H)-pyrimidinedione, 1-[9-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-6-[[[(1,1-dimethylethyl)dimethylsilyl]oxy]methyl]-2-oxo-1,7-dioxaspiro[4.4]non-8-yl]- InChI=1/C24H42N2O7Si2/c1-22(2,3)34(7,8)30-15-16-24(13-11-18(28)32-24)19(33-35(9,10)23(4,5)6)20(31-16)26-14-12-17(27)25-21(26)29/h12,14,16,19-20H,11,13,15H2,1-10H3,(H,25,27,29