Chromones and bischromones: an account of photoinduced reactions

Abstract

This account provides a survey of phototransformations of chromones occurring through the cycloadditions, oxidations, isomerizations and reorganizations. Photochemistry of the variety of bischromones occurring through intramolecular photo-H-abstractions and thus leading to angular tetracyclic photoproducts has also been reviewed. In the bischromones, the photoproduct formations and their distributions were found to be dependent upon the length and structure of the intermediate spacer units.