Identify the major reactant that undergoes an intramolecular aldol condensation to yield the given product.

Step-by-step solution

The given reaction is an intramolecular aldol condensation. To identify the correct reactant, we perform a retro-aldol analysis on the product, 1-acetyl-4-isopropylcyclopent-1-ene. In a retro-aldol cleavage of an , -unsaturated ketone, the carbon-carbon double bond is broken. The ring carbon atom bearing the electron-withdrawing acetyl group ( - COCH ₃ ) corresponds to the nucleophilic -carbon of a ketone enolate. The other double-bonded ring carbon corresponds to the electrophilic carbonyl carbon of an aldehyde. B