The pseudorotation of furanoses, in particular ribofuranoses, is often described
in terms of pseudorotation angles (P) and puckering (νmax). The endocyclic torsions
(ν) can be approximated using the relationship derived by Altona and Sundaralingam .
Using the torsions ν0-ν4 the torsions between the ring protons can be derived. Together with an appropriate Karplus equation the corresponding coupling constants can be estimated, or experimental coupling constants can be used to determine the phase (P) and puckering (νmax) of the ring.
Literature C. Altona and M. Sundaralingam; J. Am. Chem. Soc. 94 (1972) 8205-8212.
 C.A.G. Haasnoot, F.A.A.M. DeLeeuw and C. Altona; Tetrahedron 36 (1980) 2783-2792.