cis–trans Isomerism in bis(trihalogenoacetyl)polymethylbenzenes resulting from restricted rotation about carbonyl groups: 1H nuclear magnetic resonance evidence
Abstract
The presence of cis–trans isomerism at ambient temperatures in bis(trihalogenoacetyl)polymethylbenzenes (1)–(3) is demonstrated for the first time by the observation of separate 1H n.m.r. signals.