Analysis of Aldofuranosyl Rings: Unbiased Modeling of Conformational Equilibria and Dynamics in Solution.

analysis has been applied to methyl β-d-ribofuranoside () and methyl 2-deoxy-β-d--pentofuranoside () to demonstrate the ability of this new experimental method to determine multi-state conformational equilibria in solution. Density functional theory (DFT) was used to obtain parameterized equations for >20 NMR spin-coupling constants sensitive to furanose ring conformation in and , and these equations were used in conjunction with experimental spin-couplings to produce unbiased models of ring pseudorotation. These models describe two-state north-south conformational exchange consistent with results obtained from traditional treatments of more limited sets of NMR spin-couplings (e.