The chemistry of reactive lignin intermediates. Part 5. Rates of reactions of quinone methides with water, alcohols, phenols, and carboxylic acids

Abstract

The rates of reactions of the quinone methides 2-methoxy-4-methylene-6-t-butyl- and 2.6-dimethyl-4-methylenecyclohexa-2.5-dienone with water, phenols, and a wide range of alcohols and carboxylic acids have been measured. The reactions are second-order in alcohol or acid and of the order 1.5 in water. The rate constants depend on the pK_a values of the acids and the degree of substitution of the alcohols.