Identify the major product of the following reaction:

Step-by-step solution

The given reactant is 4,4-dimethylnaphthalen-1(4H)-one. When treated with acetic anhydride ( Ac₂O ), it undergoes a dienone-phenol rearrangement. The carbonyl oxygen is acylated by Ac₂O , forming an intermediate with a positive charge that delocalizes to the C3 carbon. A 1,2-methyl shift takes place from the C4 position (gem-dimethyl group) to the C3 position, creating a more stable benzylic carbocation at C4. Deprotonation at C3 restores the aromaticity of the ring, yielding a fully aromatic naphthalene system. Si