# How is a ring formed when a carbon atom in an aliphatic chain attached to benzene ring has a positive charge?

This is my approach towards this problem. First off, a positive charge would appear in the C atom at the end of the chain, and then that carbocation would rearrange into a tertiary carbocation.

But I am not being able to figure out what will be the next step. Can the carbocation extract a hydrogen from the benzene ring to form another five-membered chain as the formation of a five-membered rings is very feasible?

• Yes, Definitely. The carbocation won't extract proton from Benzene ring, the $\pi$-electron cloud of benzene ring will attack to the carbocation to form the fused five-membered ring and a proton will be lost to rearomatise the system. – Soumik Das Apr 10 '19 at 13:18
• You need to review cation rearrangements. – user55119 Apr 10 '19 at 13:52
• @SoumikDas so should the benzene ring attack from the carbon opposite to the carbon bearing the -och3 group , as then the carbanion formed would be more stable? – Pratham Yadav Apr 10 '19 at 14:40
• Yes there will be electrophilic addition at the para position to form a 5-membered ring. – Som V. Tambe Apr 10 '19 at 15:53
• @PrathamYadav Yes, I think so, as attack from the ortho position of $\ce{-OCH3}$will make lot of steric crowding, attack from para position of $\ce{-OCH3}$ should be more favoured.. – Soumik Das Apr 10 '19 at 15:55