Conjugate addition

The Robinson annelation

The mechanism of Robinson annelation involves the sequential process of a Michael addition-aldol reaction leading to a new six-membered ring. The formation of a stable enolate occurs first as shown below, here of a 1,3-diketone:

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Below are shown the three stages of the Robsinson annelation mechanism. 'Click' the different stages to view 3D models of the reaction:

R. E. Gawley, Synthesis (Stuttg)., 1976, 1976, 777–794.