(±)-1-{8′-(tert-Butyl­diphenyl­silyloxy­meth­yl)-1′,7′-dioxaspiro­[5.5]undecan-2′-yl}uridine

The crystal structure of the title compound, C(30)H(38)N(2)O(5)Si, has been investigated to establish the relative stereochemistry at the spiro ring junction and the two anomeric centres. Each of the O atoms in the tetra­hydro­pyran rings adopts an axial position on the neighbouring ring. This bis­-diaxial conformation is adopted, thus gaining maximum stablization from the anomeric effect. The silyl-protected hydroxy­methyl and uracil substituents adopt equatorial positions on their associated tetra­hydro­pyran rings, thereby minimizing unfavourable steric inter­actions. The dimeric (2′R*,6′R*,8′R*)- and (2′S*,6′S*,8′S*)-uridine units are connected to each other across crystallographic inversion centres via inter­molecular N—H⋯O hydrogen bonds.