The oxidation of l-2(10)-pinene with leadtetraacetate in glacial acetic acid at 60°C afforded, besides fifteen known other products, (1S,6S)-7,7-dimethylbicyclo [4.1.1]octan-3-one (2) and (1S,6S)-2-one isomer (3), whose structures were established on the basis of their spectroscopic data. A possible reaction pathway for the formation of these new compounds 2 and 3 involving novel ring-enlargement