Applications of high-potential quinones. Part X. Reactions of 3,4-dihydrocoumarin derivatives
Abstract
Ring opening is preferred to dehydrogenation when 3,4-dihydrocoumarins react with ortho- or para-chloranil or with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in alcoholic solvents, the quinones acting as Lewis acid catalysts. The alcoholysis products react further with DDQ to give coupled adducts.