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Wolff-Kishner reduction



The Wolff-Kishner reduction is a chemical reaction that fully reduces a ketone (or aldehyde) to an alkane.[1][2]

The method originally involved heating the hydrazone with sodium ethoxide in a sealed vessel at about 200 °C. Other bases have been found equally effective.

Several reviews have been published.[3][4]

Additional recommended knowledge

Contents

Reaction mechanism

The most probable mechanism involves the elimination of an alkyl anion as the final step:

The mechanism first involves the formation of the hydrazone in a mechanism that is probably analogous to the formation of an imine. Successive deprotonations eventually result in the evolution of nitrogen. The mechanism can be justified by the evolution of nitrogen as the thermodynamic driving force.

Huang-Minlon modification

The Huang-Minlon modification[5][6] is a convenient modification of the Wolff-Kishner reduction and involves heating the carbonyl compound, potassium hydroxide, and hydrazine hydrate together in ethylene glycol in a one-pot reaction.[7]

References

  1. ^  Kishner, N. J. Russ. Chem. Soc. 1911, 43, 582.
  2. ^  Wolff, L. Ann. 1912, 394, 86.
  3. ^  Todd, D. Org. React. 1948, 4, 378. (Review)
  4. ^  Hutchins, R. O.; Hutchins, M. K. Comp. Org. Syn. 1991, 8, 327-343. (Review)
  5. ^  Huang-Minlon J. Am. Chem. Soc. 1946, 68, 2487.
  6. ^  Huang-Minlon J. Am. Chem. Soc. 1949, 71, 3301.
  7. ^  Organic Syntheses, Coll. Vol. 4, p.510 (1963); Vol. 38, p.34 (1958). (Article)
  8. Organic Syntheses, Coll. Vol. 5, p.533 (1973); Vol. 43, p.34 (1963). (Article)

See also

 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Wolff-Kishner_reduction". A list of authors is available in Wikipedia.
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