JEE Previous Year Question

A trisubstituted compound ‘A’, $C_{10}{H}_{12}{O}_2$ gives neutral $FeC{l}_3$ test positive. Treatment of compound 'A' with NaOH and $C{H}_3$Br gives $C_{11}{H}_{14}{O}_2$, with hydroiodic acid gives methyl iodide and with hot cone. NaOH gives a compound B, $C_{10}{H}_{]2}{O}_2$. Compound 'A' also decolorises alkaline $KMn{O}_4$. The number of $\pi$ bond/s present in the compound 'A' is_______.

Topic: JEE PYQ

Answer: 4. Full step-by-step solution below.