Nuclear magnetic resonance and stereochemistry of 1,2,3,5,6,7-hexamethoxy-9,10-diethyl-9,10-dihydroanthracene, a dimer of 3,4,5-trimethoxypropenylbenzene

Abstract

Acid-catalysed dimerisation of 3,4,5-trimethoxypropenylbenzene yields 1,2,3,5,6,7-hexamethoxy-9,10-diethyl-9,10-dihydroanthracene to which the 9,10-trans-stereochemistry is allocated from the high-field methyl triplet signal in the n.m.r. spectrum.