Meerwein-Ponndorf-Verley reduction

What is Meerwein-Ponndorf-Verley reduction?

Meerwein-Ponndorf-Verley reduction, or aluminum alkoxide reduction, is the reaction of aldehydes or ketones to the corresponding alcohols with aluminum alkoxides. This reaction is the opposite of the Oppenauer oxidation.

It is named after the German chemists Hans Meerwein, Arthur Ponndorf, and Georg Verley, who first described the reaction in their research on the reduction of aldehydes or ketones..

The MPV reduction is a useful method for synthesizing alcohols from aldehydes or ketones, which are important intermediates in the production of a wide range of chemicals and pharmaceuticals. It is a two-step process that involves the formation of an aluminum alkoxide, followed by the reduction of the aldehyde or ketone..

Meerwein-Ponndorf-Verley reduction
Meerwein-Ponndorf-Verley reduction

The first step of the MPV reduction involves the formation of an aluminum alkoxide from aluminum metal and an alcohol. This is typically done by reacting aluminum metal with the alcohol in the presence of a solvent, such as tetrahydrofuran or hexane. The resulting aluminum alkoxide is a strong reducing agent and can be used in the second step of the reaction..

The second step of the MPV reduction involves the reduction of the aldehyde or ketone to an alcohol using the aluminum alkoxide as the reducing agent. This is typically done by reacting the aldehyde or ketone with the aluminum alkoxide in the presence of a solvent. The resulting product is an alcohol, with the aldehyde or ketone group reduced to a hydroxyl group..

The MPV reduction has several advantages over other methods of synthesizing alcohols from aldehyde or ketone. It is a straightforward and efficient process that can be easily scaled up for large-scale production. It also allows for the synthesis of a wide range of alcohols, with good yields and good selectivity..

Despite these advantages, the MPV reduction has some limitations. It is not suitable for the synthesis of alcohols from aldehyde or ketone with certain substituents, such as halogens, due to the high reactivity of the intermediate. It is also not suitable with certain substituents, such as electron-withdrawing groups, due to the low reactivity of the aldehydes or ketones..

Summary

The MPV reduction is an important method for the synthesis of alcohols from aldehydes or ketones, and it has played a significant role in the production of a wide range of chemicals and pharmaceuticals..

References

  • Meerwein, H. and Schmidt, R. (1925), Ein neues Verfahren zur Reduktion von Aldehyden und Ketonen. [A new process for the reduction of aldehydes and ketones.] Justus Liebigs Ann. Chem., 444: 221-238. https://doi.org/10.1002/jlac.19254440112
  • W. Ponndorf, Angew. Chem. 39, 138 (1926)
  • A. Verley, Bull. Soc. Chim. France 37, 537, 871 (1925)
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