Tishchenko reaction

The Tishchenko reaction is an organic chemical reaction that involves disproportionation of an aldehyde lacking a hydrogen atom in the alpha position in the presence of an alkoxide.^[1] The reaction product is an ester. Catalysts are aluminium alkoxides or sodium alkoxides.

In the related Cannizzaro reaction the base is sodium hydroxide and then the oxidation product is a carboxylic acid and the reduction product is an alcohol.

Examples

• Benzaldehyde reacts with sodium benzyloxide (generated from sodium and benzyl alcohol) to generate benzyl benzoate.^[2]

• The Tishchenko reaction of acetaldehyde gives the commercially important solvent ethyl acetate; it is catalyzed by aluminium alcoholate.^[3]
• The Tishchenko reaction is used to obtain isobutyl isobutyrate, a specialty solvent.^[4]
• Hydroxypivalic acid neopentyl glycol ester is produced by a Tishchenko reaction from hydroxypivaldehyde in the presence of a basic catalyst (e.g., aluminium oxide).^[5]
• The Tishchenko reaction of paraformaldehyde in the presence of aluminum methylate or magnesium methylate forms methyl formate.^[6]
• Paraformaldehyde reacts with boric acid to form methyl formate.^[7] The key step in the reaction mechanism for this reaction is a 1,3-hydride shift in the hemiacetal intermediate formed from two successive nucleophilic addition reactions, the first one from the catalyst. The hydride shift regenerates the alkoxide catalyst.

Related reactions

• Aldol–Tishchenko reaction
• Baylis–Hillman reaction
• Cannizzaro reaction
• Meerwein–Ponndorf–Verley reduction
• Oppenauer oxidation

References

1. V. Tishchenko (1908), J. Russ. Phys. Chem. Soc 38: 355, 482 Missing or empty |title= (help)
2. Kamm, O.; Kamm, W. F. (1941). "Benzyl benzoate". Org. Synth.; Coll. Vol. 1, p. 104
3. Marc Eckert, Gerald Fleischmann, Reinhard Jira, Hermann M. Bolt, Klaus Golka (2007), "Acetaldehyde", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 4
4. Boy Cornils, Richard W. Fischer, Christian Kohlpaintner (2007), "Butanals", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 4
5. Peter Werle, Marcus Morawietz (2007), "Alcohols, Polyhydric", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 6
6. Günther Reuss, Walter Disteldorf, Armin Otto Gamer, Albrecht Hilt (2007), "Formaldehyde", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 5
7. Paul R. Stapp (1973). "Boric acid catalyzed Tishchenko reactions". J. Org. Chem. 38 (7): 1433–1434. doi:10.1021/jo00947a049.