Indirect spin-spin NMR H-1-H-1 coupling constants of newly synthesized furanose monosaccharide derivatives were interpreted on the basis of ab initio modeling. Epoxy, epithio, and epimino groups were inserted into the sugars and significantly limited their conformational flexibility, which was confirmed by a systematic conformer analysis. Because of the restriction, the performance of the computations and the dependence of the coupling constants oil the geometry could be estimated more easily. Conventional Karplus equations are not optimized for this class of compounds and cannot be used for reliable interpretation of the NMR spectra. Fully analytical B3LYP/IGLOII computations of the coupling constants were performed including all the four important magnetic terms (SD, DSO, PSO, FC) in the Hamiltonian. Good agreement of the calculated and the experimental coupling constants was achieved, and computed structural parameters are consistent with available X-ray data. The influence of the different functional groups on the spin-spin coupling constants was discussed.