Dieckmann condensation

The Dieckmann condensation^[1][2][3] is the intramolecular chemical reaction of diesters with base to give β-ketoesters.^[4][5]. It is named after the German chemist Walter Dieckmann (1869–1925). The equivalent intermolecular reaction is the Claisen condensation.

Reaction Mechanism

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The acidic hydrogen between the two carbonyl groups is deprotonated in step four. Protonation with a Brønsted-Lowry acid (H₃O⁺ for example) re-forms the β-keto ester. ^[6] This deprotonation step is the driving force for this reaction.

References

1. ^ Dieckmann, W. Ber. 1894, 27, 102 & 965
2. ^ Dieckmann, W. Ber. 1900, 33, 595 & 2670
3. ^ Dieckmann, W. Ann. 1901, 317, 51 & 93
4. ^ Schaefer, J. P.; Bloomfield, J. J. Org. React. 1967, 15, 1-203. (Review)
5. ^ Davis, B. R.; Garrett, P. J. Comp. Org. Syn. 1991, 2, 806-829. (Review)
6. ^ Janice Gorzynski Smith. Organic Chemistry: Second Ed. 2008. pp 932-933.

See also

• Claisen condensation
• Gabriel-Colman rearrangement