5,8,13,17,22,25-Hexaoxanonacosanedioic acid,15-[4-[[(1,1-dimethylethyl)diphenylsilyl]oxy]-1,4-dioxobutoxy]-7,23-bis[[1,4-dioxo-4-[(cis-2-phenyl-1,3-dioxan-5-yl)oxy]butoxy]methyl]-4,9,12,18,21,26-hexaoxo-, bis(cis-2-phenyl-1,3-dioxan-5-yl) ester