Abstract
13C NMR assignments previously given for A‐nuclei (C‐5, 6, 7, 8, 9, 10) of 5‐hydroxy‐isoflavones (Ie, IIe, IIIb) have been reconsidered on the basis of the proton‐coupled spectrum of 5‐hydroxy‐7, 4′‐dimethoxyisoflavone (Ie) (cf:Bull. Soc. Chim. Belg., 76 n°6/473, 1977).Furthermore, in order to generalize the method employed to predict resonances of the aromatic carbons of the 2,2‐dimethylchromene ring, we have recorded and fully analysed the spectra of the model compound (IV) and of the 2,2‐dimethylphenylacetyl‐6‐chromenes (V) and (VI).