O2,1'-anhydro-(beta-D-psicofuranosyl)thymine and 1-(1',4'-O-anhydro-beta-D-psicofuranosyl)thymine: the crystal structures versus the 1H NMR and ab initio data.

The crystal structures of the title compounds 1 and 2 have been determined. Relation between the stereochemistry of both nucleosides in the crystal state and the (1)H NMR data in solution as well as the ab initio calculations is discussed.