Identify the major product formed in the following reaction sequence.

Step-by-step solution

The reaction sequence proceeds as follows: 1. Protection of Ketone: The starting material has both a ketone and a primary alcohol group. Reaction with ethylene glycol in the presence of an acid ( H^ ) selectively protects the ketone group by forming a cyclic ketal. The primary alcohol remains unaffected. 2. Oxidation: Collin's reagent ( CrO₃ 2C₅H₅N ) is a mild oxidizing agent that oxidizes the primary alcohol ( -CH₂OH ) to an aldehyde ( -CHO ) without affecting the ketal group. 3. Grignard Reaction: Ethylmagnesium