ABSTRACT
A wide variety of carbonyl compounds undergo photoinduced intramolecular hydrogen atom abstraction to form 1-hydroxy-1,
x
-biradicals, which then undergo two common competing reactions: (1) coupling to produce cyclic alcohols and (2) disproportionation back to ketone or to various enols. The overall process closely parallels the well-known bimolecular photoreduction of ketones, the most common products of which are formed by radical coupling. These intramolecular hydrogen abstraction processes have been widely studied, and several reviews are available.
