Abstract
Bicyclo[2,2,2]7‐octene‐2,5‐dione (1), prepared by oxidative decarboxylation of the dicarboxylic acid (3), shows a relatively intense UV.‐absorption band at 223 mμ (log ε = 3,36), which is ascribed to internal charge transfer. An unusually strong band (n → π‐transition), characteristic of non‐planar β,γ‐unsaturated ketones and resolved into two peaks at 296 and 307 mp (log ε = 2,41) respectively, is also present.