1,3-Dipolar character of six-membered aromatic rings. Part VIII. [2]Benzopyrano[4,3-b]pyridin-6-ones
Abstract
3-Hydroxypyridine (1b), its 6-methyl analogue (1a), and 3-hydroxyquinoline (14) each react with the benzyne precursor phenylium-2-carboxylate (16) to give the [2]benzopyrano[4,3-b]pyridin-6-ones (6b), (6a), and (15).