Novel spirocyclization based on intramolecular 1,4-addition and its asymmetric version have been developed using a combination of Lewis acid and 1,2-diol. Treatment of five- and six-membered α,β-unsaturated cyclic ketones having a 4-oxopentyl group at the β-position with Lewis acid and ethylene glycol gave spiro[4.5]decane-2,7-dione and spiro[5.5]undecane-2,8- done, respectively. The asymmetric version of this reaction has been developed by using optically active 1,2-diol such as cyclohexane-1,2-diol to afford the spirocyclic products of up to 85% e.e.
All Science Journal Classification (ASJC) codes
- Drug Discovery
- Organic Chemistry