Answer:
Michael adition and Aldol Condensation
Step-by-step explanation:
Robinson annulation involves two sequencial reactions. This is a typical reaction between a α, β unsatured vynil ketone and a ketone.
The first reaction is the michael adition. In this step, a strong base such a NaOH, substract an hydrogen atom from the vynil ketone, which them, reacts with the other ketone (Double bond in the compound) and form an enolate. This enolate intermediate must be tautomerized and the conversion can continue.
The second reaction involves the aldol condensation, which the enolate (already tautomerized) reacts with the other carbonile in the compound, and the water of the medium, to transform that carbonile into a great outgoing group, and then, it formed a polyciclic compound of at least six membered ring.
The picture is an example of the mechanism of reaction of this annulation. From A to C, is the first step. From D to F is the second step of reaction.