Chemistry - GOC Question with Solution | TestHub

Compound (k) is a benzene-fused cyclohexadienyl cation. One ring carbon (upper right) is sp3 (CH2), so the conjugated pi network is the benzene ring plus the C+ to C=C path.

Shift the pi electrons so the positive charge sits on each allowed atom:

1) Benzylic C (structure as drawn, benzene Kekule form A)

2) Benzylic C (benzene Kekule form B)

3) Ortho carbon of the benzene ring

4) Para carbon of the benzene ring

5) Ring-junction (fusion) carbon next to the C=C bond

6) Far carbon of the C=C bond (allylic shift)

The meta ring carbon and the sp3 carbon cannot carry the charge.

Total resonating structures = 6.