Oxidation of (E)- and (Z)-2,6-Dimethoxy-4-propenylphenol with ferric chloride–a facile route to the 2-aryl ethers of 1-Arylpropan-1,2-diols

Abstract

Oxidation of both (E)- and (Z)-2,6-dimethoxy-4-propenylphenol (3c) and (3d) with 1 equiv. of ferric chloride gives the 2-aryl ethers of erythro and threo 1-arylpropan-1,2-diols (1) and (2) (55%) which are formed by C-O coupling. The configurations of aryl ethers (1) and (2) were determined from p.m.r. and i.r. spectral data. Other products of the oxidation of phenol (3c) include the C-C-coupled 1-aryltetralin isomers (4) and the dihydronaphthalene (5), the 1-arylindane dimer (6), and 2,6-dimethoxy-1,4-benzoquinone. Oxidation of phenol (3c) with excess ferric chloride yields some oligomeric C-O-coupled material in addition to compounds (1) and (2).