Identify the major product formed in the following reaction sequence:

Step-by-step solution

Reductive ozonolysis of 1-methylcyclopentene cleaves the C=C double bond to form a dicarbonyl compound. The methyl-substituted carbon becomes a ketone, and the unsubstituted carbon becomes an aldehyde. The intermediate product 'A' is 5-oxohexanal: CH ₃- C (= O )- CH ₂- CH ₂- CH ₂- CHO . Treatment of 'A' with Toluene-4-sulphonic acid (a strong acid) and heat ( ) initiates an acid-catalyzed intramolecular aldol condensation. Enolization occurs at the terminal methyl group, and the resulting nucleophilic enol carbon a