Structural and Solvent/Electrolyte Effects on the Selectivity and Efficiency of the Anodic Oxidation of Para-Substituted Aromatic Ethers. An Efficient Route to Quinol Ether Ketals and Quinol Ethers

Article abstract of DOI:10.1021/jo00231a022

The anodic oxidations of the methyl ethers of p-arylphenols C6H4, o-<(H3CO)2HC>C6H4, o-HO2CC6H4>, the 2-hydroxyethyl ethers of p-arylphenols , and the 2-hydroxyethyl ethers of p-alkylphenols and 4-methyl-1-naphthol were studied.The p-aryl aromatic ethers underwent anodic oxidation in good yield to give the corresponding p-quinol ether ketals.The ratio of nuclear to side-chain products from anodic oxidation of p-alkylanisole derivatives is dependent upon the electrolysis conditions.The 2-hydroxyethyl ether derivatives of p-alkylphenols markedly favor the formation of nuclear oxidation products - providing a useful route to the corresponding p-quinol ether ketals.In addition, methanolic potassium fluoride improves the efficiency of these anodic oxidation processes by about 400percent relative to methanolic potassium hydroxide.These reactions were performed at a constant current (1.0-2.0 A) in a single cell and serve as preparative routes to p-quinol ether ketals and quinol ethers via acid hydrolysis.