Benzene is treated successively with (i) CH3CH2CH2COCl, anhydrous AlCl3 and (ii) Zn(Hg), conc. HCl. The final product is

JEE Main levelSingle correct optionDifficulty 2 of 3o2137

Benzene is treated successively with (i) $CH X_{3} CH X_{2} CH X_{2} COCl$ , anhydrous $AlCl X_{3}$ and (ii) $Zn (Hg)$ , conc. HCl. The final product is

The acylium ion

CH X_{3} CH X_{2} CH X_{2} - C X^{+} = O

does not rearrange, giving 1-phenylbutan-1-one. Clemmensen reduction converts the

C = O

group into

CH X_{2}

, so the unbranched n-butylbenzene results. Direct alkylation would have rearranged.