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Prediction of anti and gauche vicinal proton‐proton coupling constants in carbohydrates: A simple additivity rule for pyranose rings
Author(s) -
Altona Cornelis,
Haasnoot Cornelis A. G.
Publication year - 1980
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270130606
Subject(s) - pyranose , additive function , chemistry , vicinal , coupling constant , computational chemistry , electronegativity , proton , stereochemistry , homogeneity (statistics) , crystallography , organic chemistry , mathematics , physics , mathematical analysis , quantum mechanics , statistics
The effect of the relative orientation and electronegativity of substituents on the magnitude of 3 J (aa), 3 J (ae) and 3 J (ee) is well predicated by a simple set of additivity constants, valid for pyranose rings in carbohydrates. The proposed set of parameters is used to calculate 327 coupling constants [ 3 J (HH)] in a variety of pyranosides and related compounds. A comparison with experimental values taken from the literature shows that couplings in molecules which are conformationally pure and underformed can be predicted with a surprising accuracy. An overall root‐mean‐square agreement of 0.29 Hz is attained for a selected group of 305 coupling values. A statistical breakdown of Δ J (aa) and Δ J (ae) [Δ J = J (exp)‐ J (calc)] along each carbon‐carbon bond in the pyranose systems reveals an unexpected degree of geometrical homogeneity.