Interconversion of stereolabile meso and racemic diastereoisomers of hindered 1,4-diacylnaphthalenes

Derivatives of 1,4-diacylnaphthalenes were examined to determine the relationship between the dimension of the carbonyl-bonded alkyl groups and the interconversion barriers. Structural assignment was made possible by observing the conformer ratio at equilibrium with respect to the solvent polarity. For the bulky tert-butyl derivative, both isomers were isolated at low temperature and, by using X-ray data, the solid-state assignment was transferred to solution nuclear magnetic resonance signals under nonequilibrium conditions.