Step 2: Intramolecular aldol reaction
Click the structures and reaction arrows in sequence to view the 3D models and animations respectively
The next step is the formation of a new enolate on the other side of the ketone from the first. Note that the original enolate, the intermediate in the conjugate addition, can cyclize to give only an unstable four-membered ring so this cyclization would be reversible. The next intermediate, the aldol product, is often isolated from Robinson annelations.