Étard reaction

It is named for the French chemist Alexandre Léon Étard (5 January 1852, Alençon – 1 May 1910).

The Étard complex is then decomposed by a [2,3] sigmatropic rearrangement under reducing conditions to prevent further oxidation to a carboxylic acid.

Reducing conditions for the decomposition of the Étard complex are provided by saturated aqueous sodium sulphite.

[5][6] The Étard reaction is most commonly used as a relatively easy method of converting toluene into benzaldehyde.

Obtaining specific aldehyde products from reagents other than toluene tends to be difficult due to rearrangements.