Question

The major product 'A' of the following given reaction has sp² hybridized carbon atoms.

2, 7-Dimethyl-2, 6-octadiene $\xrightarrow{H^+}$ A

Answer 1

The major product is 1,1,4,4,6-pentamethylcyclohex-5-ene, a cyclic alkene with sp² hybridized carbon atoms in the double bond.

Answer 2

The reaction proceeds via electrophilic addition to the diene. Protonation of the C2=C3 double bond at C3 yields a tertiary carbocation at C2. This carbocation then undergoes an intramolecular cyclization by attacking the C6=C7 double bond at C6, forming a six-membered ring and a tertiary carbocation at C7. Finally, deprotonation from C6 generates the alkene, resulting in the formation of 1,1,4,4,6-pentamethylcyclohex-5-ene. This cyclic product contains sp² hybridized carbon atoms at the double bond, satisfying the condition given in the question.