Aldol condensation
An aldol condensation is a condensation reaction in organic chemistry in which two carbonyl moieties (of aldehydes or ketones) react to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), and this is then followed by dehydration to give a conjugated enone.
| Aldol condensation | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Reaction type | Condensation reaction | ||||||||
| Reaction | |||||||||
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| Conditions | |||||||||
| Temperature | +Δ, ~100°C | ||||||||
| Catalyst | −OH or H+ | ||||||||
| Identifiers | |||||||||
| Organic Chemistry Portal | aldol-condensation | ||||||||
| RSC ontology ID | RXNO:0000017 | ||||||||
The overall reaction equation is as follows (where the Rs can be H)
Aldol condensations are important in organic synthesis and biochemistry as ways to form carbon–carbon bonds.
In its usual form, it involves the nucleophilic addition of a ketone enolate to an aldehyde to form a β-hydroxy ketone, or aldol (aldehyde + alcohol), a structural unit found in many naturally occurring molecules and pharmaceuticals.
The term aldol condensation is also commonly used, especially in biochemistry, to refer to just the first (addition) stage of the process—the aldol reaction itself—as catalyzed by aldolases. However, the first step is formally an addition reaction rather than a condensation reaction because it does not involve the loss of a small molecule.