Question

The major product of the following reaction is

\xrightarrow[\text{(ii)H^+, heat}]{\text{(i)KOH, H_2O}}

Answer 1

4a-methyl-4a,5,6,7,8,8a-hexahydro-1(4H)-naphthalenone

Answer 2

The reaction is an intramolecular aldol condensation followed by dehydration. The diketone reactant has multiple alpha-hydrogens. Deprotonation at C6 of the cyclohexanone and subsequent attack on the side-chain ketone (C3') forms a stable 6-membered ring. This intermediate $\beta$-hydroxy ketone then undergoes acid-catalyzed dehydration to form an $\alpha$,$\beta$-unsaturated ketone, which is thermodynamically favored due to conjugation. The final product is 4a-methyl-4a,5,6,7,8,8a-hexahydro-1(4H)-naphthalenone.