Which class of compound is cinnamaldehyde, produced by the cross-aldol reaction between benzaldehyde and acetaldehyde followed by dehydration?

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Multiple Choice

Which class of compound is cinnamaldehyde, produced by the cross-aldol reaction between benzaldehyde and acetaldehyde followed by dehydration?

The reaction creates a carbonyl compound with a carbon–carbon double bond right next to the carbonyl group, giving an α,β-unsaturated aldehyde. In this cross-aldol, the enolate from acetaldehyde adds to benzaldehyde and, after dehydration, forms cinnamaldehyde with the structure Ph–CH=CH–CHO. That placement of the C=C bond adjacent to the aldehyde is what defines it as an α,β-unsaturated aldehyde. It’s not benzaldehyde itself (the product has an extra two-carbon chain and a double bond), not a saturated aldehyde (there is a C=C bond), and not a ketone (the functional group present is an aldehyde).

The reaction creates a carbonyl compound with a carbon–carbon double bond right next to the carbonyl group, giving an α,β-unsaturated aldehyde. In this cross-aldol, the enolate from acetaldehyde adds to benzaldehyde and, after dehydration, forms cinnamaldehyde with the structure Ph–CH=CH–CHO. That placement of the C=C bond adjacent to the aldehyde is what defines it as an α,β-unsaturated aldehyde. It’s not benzaldehyde itself (the product has an extra two-carbon chain and a double bond), not a saturated aldehyde (there is a C=C bond), and not a ketone (the functional group present is an aldehyde).

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