A new approach to fused carbocycles. Intramolecular photocyclisations of 1,3-dione enol acetates

Abstract

Irradiation of the enol acetate (1) gave the tricyclic adduct (2) regioselectively and in quantitative yield, whereas (12) led (93%) to a mixture (3:2) of adducts (13) and (14), and the enol acetates (9) and (10) produced mainly the photo-Fries rearrangement products (8) and (11), respectively; hydrolytic cleavage of the tricyclic adducts (2) and (14) gave rise to the bicyclo[6.3.0]undecane (3) and bicyclo[5.3.0]decane (15) ring systems.