Expedient synthesis of bicyclo[3.2.1] octanes and bicyclo [3.3.1] nonanes via the double Michael addition to cyclic dienones

We report the expedient synthesis of 8-disubstituted bicyclo[3.2.1]octane- 3-ones and 9-disubstituted bicyclo[3.3.1] octane-3-ones through the double Michael addition (DMA) of carbon nucleophiles to 7 and 8-membered ring dienones. The reaction proceeds in 4296% yield with an interesting control of the stereochemistry of the bridged secondary, tertiary or quaternary centre.