Photorearrangement of isochromens into indene epoxides
Abstract
Irradiation of 3,4-disubstituted isochromens in methanol give indene epoxides which produce ring-opened hydroxy-ethers on further irradiation; the mechanism involves opening of the isochromen ring to an o-quinonoidal intermediate which undergoes a subsequent intramolecular 4 + 2 cycloaddition reaction.