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

Abstract

The crystal structure of the title compound, C30H38N2O5Si, 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.