Consider the following reaction sequence: [X] Identify the major product [Z] .

Step-by-step solution

The given reaction sequence involves three main steps: 1. Formation of [X]: The starting material, 2-(3-oxobutyl)cyclohexanone, undergoes an intramolecular aldol condensation in the presence of dilute base ( OH^- ) and heat. The enolate formed at the terminal methyl group of the side chain attacks the cyclohexanone carbonyl carbon, forming a new six-membered ring. Subsequent dehydration yields the bicyclic , -unsaturated ketone, ^ 1,9 -octalin-2-one (or 4,4a,5,6,7,8-hexahydronaphthalen-2(3H)-one) as product [X]. 2.