When 2-allylphenol is treated with I ₂ in the presence of NaHCO ₃ , the major organic product formed is:

Step-by-step solution

The reaction is an intramolecular iodoetherification. First, iodine reacts with the double bond of the allyl group to form a cyclic iodonium ion intermediate. The phenolic oxygen then acts as an internal nucleophile. According to Baldwin's rules, the 5-exo-tet cyclization is kinetically favored over the 6-endo-tet cyclization. Thus, the oxygen attacks the internal carbon of the iodonium ion, opening the three-membered ring to form a five-membered oxygen-containing ring. The base ( NaHCO ₃ ) neutralizes the protons