Aldol condensation

Aldol condensation
Reaction type Condensation reaction
Reaction
Ketone or Aldehyde
+
Ketone or Aldehyde
↓
α,β-unsaturated Aldehyde
or
α,β-unsaturated Ketone
Conditions
Temperature
+Δ, ~100°C[a]
Catalyst
−OH or H+
Identifiers
Organic Chemistry Portal aldol-condensation
RSC ontology ID RXNO:0000017

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.

The overall reaction equation is as follows (where the Rs can be H) Aldol condensation overview

Aldol condensations are important in organic synthesis and biochemistry as ways to form carbon–carbon bonds.[2][3][4][5]

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.[6][7][8]

The Aldol reaction
The Aldol reaction

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.

  1. ^ Klein, David R. (December 22, 2020). Organic chemistry (4th ed.). Hoboken, NJ: Wiley. p. 1014. ISBN 978-1-119-65959-4. OCLC 1201694230.
  2. ^ Smith, M. B.; March, J. (2001). Advanced Organic Chemistry (5th ed.). New York: Wiley Interscience. pp. 1218–1223. ISBN 0-471-58589-0.
  3. ^ Carey, Francis A.; Sundberg, Richard J. (1993). Advanced Organic Chemistry Part B Reactions and Synthesis (3rd ed.). New York, NY: Plenum. pp. 55. ISBN 0-306-43440-7.
  4. ^ Wade, L. G. (2005). Organic Chemistry (6th ed.). Upper Saddle River, NJ: Prentice Hall. pp. 1056–1066. ISBN 0-13-236731-9.
  5. ^ Mahrwald, R. (2004). Modern Aldol Reactions. Vol. 1, 2. Weinheim, Germany: Wiley-VCH. pp. 1218–1223. ISBN 3-527-30714-1.
  6. ^ Heathcock, C. H. (1991). Additions to C-X π-Bonds, Part 2. Comprehensive Organic Synthesis. Selectivity, Strategy and Efficiency in Modern Organic Chemistry. Vol. 2. Oxford: Pergamon. pp. 133–179. ISBN 0-08-040593-2.
  7. ^ Mukaiyama T. (1982). "The Directed Aldol Reaction". Organic Reactions. 28: 203–331. doi:10.1002/0471264180.or028.03. ISBN 0471264180.
  8. ^ Paterson, I. (1988). "New Asymmetric Aldol Methodology Using Boron Enolates". Chemistry and Industry. 12. London: Paterson Group: 390–394.


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