The correct structure of the product $A$ formed in the following reaction is: $\mathrm{cyclohex}\text{-}2\text{-}\mathrm{en}\text{-}1\text{-}\mathrm{one}\underset{\text{Pd/C, EtOH}}{\overset{\text{H2 (1 atm)}}{\to }}\mathrm{A}$

Solution & Explanation

\textbf{Answer:} (B) cyclohexanone \textbf{Solution:} In cyclohex-2-en-1-one, catalytic hydrogenation with $\mathrm{H}{}_2$/Pd-C at low pressure (1 atm) selectively reduces the less hindered, more reactive $\mathrm{C}=\mathrm{C}$ double bond while leaving the carbonyl group intact. The conjugated alkene of the enone is hydrogenated, so the product $A$ is cyclohexanone. The carbonyl is not reduced under these mild conditions.