O5−C6
O2−C3
C4−O5
C1−O2
On the treatment of the given compound with a strong acid, the most susceptible site for bond cleavage is O5−C6. The lone pair of electrons on O2 is involved in resonance with C=C. Hence, O2 will not be protonated. The lone pair of electrons on O5 is not involved in resonance with C=C. Hence, O5 will be protonated. Chloride ion will then attack least substituted C atom (C6)