(3-((2R,3R,4R,5R)-4-((bis(phenylthio)phosphoryl)oxy)-3-((tetrahydro-2H-pyran-2-yl)oxy)-5-((tris(4-(5,6-dichloro-1,3-dioxoisoindolin-2-yl)phenyl)methoxy)methyl)tetrahydrofuran-2-yl)-2,6-dioxo-3,6-dihydropyrimidin-1(2H)-yl)methyl pivalate