Acta Crystallographica Section E (Jan 2011)
3′-O-Acetyl-2′-deoxyuridine
Abstract
In the two independent but very similar molecules of the title compound, C11H14N2O6, both nucleobase fragments are nearly planar (both within 0.01 Å) while the furanose rings exhibit 2E-endo envelope conformations. In the crystal, the two 3′-O-acetyl-2′-deoxyuridine molecules form a pseudosymmetric dimer of two bases connected via two nearly identical resonance-assisted N—H...O hydrogen bonds. The resulting pair is further connected with neighboring pairs via two similar O—H...O bonds involving the only hydroxyl group of the 2′-deoxyfuranose fragment and the remaining carbonyl oxygen of the nucleobase. These interactions result in the formation of an infinite `double band' along the b axis that can be considered as a self-assembled analogue of a polynucleotide molecule with non-canonical Watson–Crick base pairs. The infinite chains of 3′-O-acetyl-2′-deoxyuridine pairs are additionally held together by C—H...O interactions involving C atoms of the uracyl base and O atoms of carbonyl groups. Only weak C—H...O contacts exist between neighboring chains.