Photochemie von Benzisoxazolen. (vorläufige Mitteilung)

Abstract

Abstract The photochemical behaviour of benzisoxazoles 1 is remarkably solvent‐dependent: Irradiation in H 2 O or CH 3 O or CH 3 OH leads to benzoxazoles 2 in a virtually quantitative yield. However, at low concentrations of H 2 O or CH 3 OH in acetonitrile or hexane, photolysis of 3‐alkyl‐benzisoxazoles 1b–1e yields salicylamides 4 and salicylesters 5 , while under these conditions o ‐cyanophenol ( 3a ) is the only photoproduct of benzisoxazole ( 1a ). The course of these photochemical reactions is discussed from the standpoint of solvent‐dependence, multiplicity and the behaviour at low temperatures.