No abstract

Effects of side-chain hydroxyl groups on pyrolytic β-ether cleavage of phenolic model dimers were studied with various deoxygenated dimers under the pyrolysis conditions of N2 / 400 o C / 1min. Although phenolic dimer with hydroxyl groups at Cα-and Cγ-positions was much more reactive than the corresponding non-phenolic type, deoxygenation at the Cγ-position substantially reduced the reactivity up to the level of the non-phenolic type. These results are discussed with the cleavage mechanism via quinone methide intermediate formation, which is activated through intramolecular hydrogen bonds between Cα-and Cγ-hydroxyl groups.