JEE Main · 2026 · 02 Apr 2026 · Shift 2 · Hydrocarbons

The compound (X) on
(i) on heating in the presence of anhydrous

AlCl_{3}

and HCl gas gives 2, 4-dimethyl pentane
(ii) aromatization gives toluene and
(iii) cyclisation gives methyl cyclohexane

The correct name of compound

(X)

is :

(A)Hept-2-ene
(B)Hept-1,3,5-triene
(C)Heptane✓ Correct
(D)Hept-2,4,6-triene

Answer: (C)

Solution

Each transformation points to a straight-chain

C X_{7} H X_{16}

skeleton. Heating with anhydrous

AlCl X_{3}

and HCl isomerises

n

-heptane to the branched isomer 2,4-dimethylpentane; aromatisation by dehydrocyclisation converts it to toluene, a

C X_{7}

aromatic; and ring closure gives methylcyclohexane. All three products keep seven carbons and are produced only from the unbranched alkane, so compound X is heptane.

JEE Main · 2026 · 02 Apr 2026 · Shift 2 · Single correct option

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