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1. Formation of the Carbocation (Protonation)

The reaction uses hydrofluoric acid ($$\text{HF}$$) as an acid catalyst. The exocyclic double bond of methylenecyclohexane undergoes protonation according to Markovnikov's rule:

• The $$H^+$$ from $$\text{HF}$$ adds to the terminal carbon ($$=\text{CH}_2$$), converting it into a methyl group ($$-\text{CH}_3$$).
• This creates a highly stable tertiary ($$3^\circ$$) carbocation at the ring carbon (the 1-methylcyclohexyl cation).

2. Electrophilic Aromatic Substitution (Friedel-Crafts Alkylation)

Benzene acts as the nucleophile and attacks this stable tertiary carbocation:

• The $$\pi$$-electrons of the benzene ring attack the positively charged carbon atom of the 1-methylcyclohexyl cation.
• Subsequent deprotonation restores the aromaticity of the benzene ring.