PHOTOREACTIONS OF KETONES IN STRONG ACID MEDIA. A NOVEL TYPE REARRANGEMENT IN CYCLIC Β-Dicarbonyl SYSTEM

Abstract

Cyclic β-dicarbonyl compounds 1a, 1b, 10a and 10b undergo isomerization involving reconstruction of the ring system by the UV-irradiation in strong acid media. It is suggested that the isomerization is aided by the formation of stabilized cation after the ring opening.