Aldol condensation
Aldol condensation allows the formation of C-C bonds. It is commonly used to manufacture solvents (diacetone alcohol and isophorone), intermediates for the manufacture of perfumes and pharmaceuticals (chalcones and more generally a,b unsaturated ketones) and plasticizers. The aldolization can be catalyzed by acids or bases, but base catalysis is usually preferred.
Aldolization of acetone
Examples
- Condensation of acetone to diacetone alcohol can be readily catalyzed by various weak base (Amberlyst™ A21) and strong base (Amberlyst™ A26) polymeric catalysts.
- The aldol condensation of citral with acetone at 55°C under a strong base gel resin catalyst (Amberlite™ IRA400) in replacement of sodium hydroxide has been studied. 90-95% conversion was obtained with 5-10% unreacted citral. The resulting product is pseudoionone which is a commercial intermediate for the production of flavours like alpha and beta ionones and also for the synthetic production of vitamins.
- A. Kinetic study of the aldol condensation of n-butyraldehyde with formaldehyde over a weak bas gel resin catalyst has been studied bySerra-Holm.
Recommended Catalysts
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Weak base macroporous polystyrene based catalyst. |
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Type 1, strong base macroporous polystyrene based catalyst. |
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| Amberjet™ 4400 OH | Type 1, strong base gel type. |
For sampling, pricing and availability of AMBERLYST™ catalysts please contact your Rohm and Haas sales representative.
Further Reading
- V. Serra-Holm, T. Salmi, J. Multamäki, J. Reinik, P. Mäki-Arvela, R. Sjöholm, L.P. Lindfors "Aldolization of butyraldehyde with formaldehyde over a commercial anion-exchange resin -kinetics and selectivity aspects" Applied Catalysis A: General 198 (2000) 207-221.
- G.G. Podrebarac, F.T.T. Ng, G.L. Rempel "A kinetic study of the aldol condensation of acetone using an anion exchange resin catalyst", Chemical engineering Science, vol 52, N° 17, pp 2991-3002 (1997).
