Robinson Annulation
The synthetic sequence of a Michael (conjugate) addition followed by an intramolecular aldol condensation, leading to a cyclohexenone, is called the Robinson annulation.
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In the first step, the enolate of an aldehyde, a ketone or a dicarbonyl compound attacks an α,β-unsaturated ketone in a conjugate fashion.
In the second step, the enolate formed in the conjugate addition attacks intramolecularly the carbonyl group that started the reaction. The most stable ring (six-membered) is formed, and a cyclohexenone is obtained after the dehydration typical of aldol condensations.
The reaction is named after Robert Robinson, who described it in 1935.