The electrochemical methoxylation of dialkoxyaromatic compounds and the determination of isomer ratios by n.m.r. spectroscopy
Abstract
Electrolysis in methanol–KOH solution of p-diethoxy-, p-di-n-propoxy-, p-di-isopropoxy-, p-di-n-butoxy-, p-di-isobutoxy-, and p-di-s-butoxy-benzenes afforded the corresponding 3,6-dialkoxy-3,6-dimethoxycyclohexa-1,4-diene, shown by 1H n.m.r. spectroscopy to be an approximately equimolar mixture of cis-and trans-isomers. Likewise, from 9,10-diethoxyanthracene was obtained an equimolar mixture of the cis- and trans-isomers of 9,10-diethoxy-9,10-dimethoxy-9,10-dihydroanthracene.