Identify the major product formed in the following reaction sequence:

Step-by-step solution

The given starting material is fluorenone, which contains a five-membered ring with a ketone group flanked by two benzene rings. Step (i): Reaction with diazomethane ( CH ₂ N ₂ ) leads to the homologation of the ketone (ring expansion). The nucleophilic carbon of diazomethane attacks the carbonyl carbon, followed by the migration of an aryl bond and the expulsion of nitrogen gas ( N ₂ ). This expands the five-membered ring to a six-membered ring, forming phenanthren-9(10H)-one. Phenanthren-9(10H)-one readily underg