Identify the type of reaction shown below:

Step-by-step solution

The given reactant is 6-oxoheptanal, which contains both an aldehyde and a ketone functional group. In the presence of a base ( OH^- ), an intramolecular aldol condensation takes place. The base abstracts an -hydrogen to form an enolate. The enolate formed at the C₅ position ( to the ketone) attacks the more electrophilic carbonyl carbon of the aldehyde group ( C₁ ). This intramolecular nucleophilic addition results in the formation of a stable 5-membered cyclic alkoxide intermediate, which upon protonation gives a