In a Grignard reaction, reacting a Grignard reagent with acetone produces what type of alcohol after aqueous workup?

In a Grignard reaction, reacting a Grignard reagent with acetone produces what type of alcohol after aqueous workup?

• A. Primary alcohol
• B. Secondary alcohol
• C. Tertiary alcohol
• D. No reaction

Answer: (C)

Grignard reagents act as nucleophiles toward carbonyl compounds. When a RMgX reagent reacts with a ketone like acetone, the carbon of the Grignard adds to the carbonyl carbon, forming a tetrahedral alkoxide intermediate: R-C(OMgX)(CH3)(CH3). After aqueous workup, this alkoxide is protonated to give the alcohol. Because acetone brings two alkyl groups (two methyls) to the carbonyl carbon and the Grignard contributes its own R group, the resulting product has three carbon substituents attached to the same carbon, making it a tertiary alcohol.

Grignard reagents act as nucleophiles toward carbonyl compounds. When a RMgX reagent reacts with a ketone like acetone, the carbon of the Grignard adds to the carbonyl carbon, forming a tetrahedral alkoxide intermediate: R-C(OMgX)(CH3)(CH3). After aqueous workup, this alkoxide is protonated to give the alcohol. Because acetone brings two alkyl groups (two methyls) to the carbonyl carbon and the Grignard contributes its own R group, the resulting product has three carbon substituents attached to the same carbon, making it a tertiary alcohol.