
%0 Journal Article
%A Jones, AJ 
%A Elix, JA 
%A Engkaninan, U 
%T The structure of the lichen depsidone hydroxyphysodic acid. A carbon-13 magnetic resonance study
%J Australian Journal of Chemistry
%D 1976/09/01
%V 29
%N 9
%P 1947-1954
%K 
%R https://doi.org/10.1071/CH9761947
%U https://www.publish.csiro.au/paper/CH9761947 
%X Unequivocal evidence for the structure of the lichen depsidone 3-hydroxyphysodic acid has been provided by analysis of long-range carbon-13-hydrogen coupling interactions and carbon-13 chemical shifts. This approach was also used to establish the isocoumarin structure (16) for that of the key decarboxycyclodehydration product obtained by degradation of 3-hydroxyphysodic acid. The breakdown of some carbon-13 additivity effects in the sterically congested ring is discussed. A possible mechanism for the formation of the isocoumarin (16) is outlined. 
