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

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 pKa values of the acids and the degree of substitution of the alcohols.