In a Claisen-Schmidt condensation between benzaldehyde and acetophenone, what is the product?

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Multiple Choice

In a Claisen-Schmidt condensation between benzaldehyde and acetophenone, what is the product?

Claisen-Schmidt condensations form an α,β-unsaturated ketone when an enolate from a ketone with an α-hydrogen attacks an aldehyde that lacks α-hydrogens, followed by dehydration. Here, acetophenone forms the enolate and attacks benzaldehyde’s carbonyl. After proton transfer, a β-hydroxy ketone intermediate forms and, under the reaction conditions, loses water to become a conjugated enone. The product is 1,3-diphenyl-2-propen-1-one, a chalcone-type α,β-unsaturated ketone with a conjugated system linking the two phenyl rings. It’s not the starting materials themselves, and it’s not the saturated ketone that would result if dehydration did not occur.

Claisen-Schmidt condensations form an α,β-unsaturated ketone when an enolate from a ketone with an α-hydrogen attacks an aldehyde that lacks α-hydrogens, followed by dehydration. Here, acetophenone forms the enolate and attacks benzaldehyde’s carbonyl. After proton transfer, a β-hydroxy ketone intermediate forms and, under the reaction conditions, loses water to become a conjugated enone. The product is 1,3-diphenyl-2-propen-1-one, a chalcone-type α,β-unsaturated ketone with a conjugated system linking the two phenyl rings. It’s not the starting materials themselves, and it’s not the saturated ketone that would result if dehydration did not occur.

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