4,7-Ethano-1H-indene, octahydro- → Decahydro-1,6-methanonaphthalene

A solution of 15 g (0.1 mole) of tricyclo[5.2.2.02,6 ] -undecane (I) in 100 ml of methylene chloride was agitated at 0°C. Then, 1.3 (0.01 mole) of anhydrous aluminum chloride was added to the solution, and the mixture was heated and refluxed under agitation for 1 hour. The reaction mixture was allowed to cool and then poured over 100 ml of ice water. The organic layer was separated and the aqueous layer was extracted with methylene chloride. The methylene chloride extract was combined with the organic layer, and the mixture was washed with a saturated aqueous solution of sodium hydrogencarbonate and then with water, and then dried over anhydrous sodium sulfate. Methylene chloride was distilled off, and the residue was subjected to fractionation. The highest boiling point fraction (boiling at 111° to 112°C. under 36 mmHg) was separated, whereby 6.3 g (yield: 42%) of tricyclo[5.3.1.03,8 ]-undecane was obtained.