bicyclo[3.2.1]octane-2,4-dione

868946-82-1

74896-14-3

Preparation of bicyclo[3.2.1]octane-2,4-dione: To a chlorobenzene solution containing 29 g (6.3% w/w, absolute mass 1.83 g, 9.1 mmol) of bromo-bicyclo[3.2.1]oct-3-en-2-one was added 50 ml of acetonitrile and 100 ml of 10% sulphuric acid, and the reaction mixture was stirred for 90 min at reflux temperature (~70 °C). Subsequently, another 50 ml of acetonitrile was added and stirring was continued for 17 hours until the reaction was complete (the progress of the reaction was monitored by HPLC). Upon completion of the reaction, acetonitrile and most of the chlorobenzene were removed using a rotary evaporator. The residue was extracted with 100 ml of ethyl acetate and the aqueous phase was separated. The organic phase was dried over magnesium sulfate, filtered and concentrated in vacuum to remove the solvent, resulting in 0.86 g (68% yield) of bicyclo[3.2.1]octane-2,4-dione. Mass spectral (MS) data: 138 (M+), 109, 96, 81, 68, 55, 39. 1H NMR (CDCl3) data: 1.80-2.15 (m, 6H), 2.95 (s, 2H), 3.05-3.15 (d, 1H), 3.20-3.30 (d, 1H).