Conformation of non‐aromatic ring compounds‐80: Calculation of dihedral angles from vicinal proton coupling constants in mono‐ and di‐substituted glutaric anhydrides

Abstract

AbstractThe Lambert‐Buys R‐value method is applied to several six‐membered α‐mono‐α,α‐ and trans‐α,α′‐di‐substituted glutaric anhydrides. A discussion concerning the appearance of the AA′BB′ spectra of the compounds under consideration is given. The vicinal proton coupling constants Jtrans (7.3‐8.1 Hz) and Jcis (4.9‐6.4 Hz) and the corresponding ring dihedral angles (ψ: 49°‐53°) are reported. The results are interpreted in terms of small deformations of the “sofa” conformation due to steric effects of the substituents.