Isovaleraldehyde

Isovaleraldehyde organic compound, also known as 3-methylbutanal, with the formula (CH3)2CHCH2CHO. It is an aldehyde, a colorless liquid at STP, and found in low concentrations in many types of food. Commercially it is used as a reagent for the production of pharmaceuticals, perfumes and pesticides.

Synthesis
Synthetic routes for the production of isovaleraldehyde vary. One method is by the hydroformylation of isobutene:
 * (CH3)2C\dCH2 + H2  + CO  → (CH3)2C\sCH2CHO

A small amount of 2,2-dimethylpropanal ((CH3)2C\sC(CHO)CH3 side product is also generated.

Another method of production involves the isomerization of 3-methylbut-3-en-1-ol using CuO–ZnO as a catalyst. A mixture of 3-methylbut-3-en-1-ol and 3-methylbut-2-en-1-ol may also be used. These starting materials are obtained from a reaction between isobutene and formaldehyde:
 * CH3CH3CCH2 + CH2O → (CH3)2CHCH2CHO

Finally, in beer the compound is produced via a reaction between the amino acid leucine and reductones in the malt.

Occurrences and uses
As it can be derived from leucine, the occurrence of isovaleraldehyde is not limited to beer. The compound has found to be a flavor component in many different types of foods. It is described as having a malty flavor and has been found in cheese, coffee, chicken, fish, chocolate, olive oil, and tea. The compound is used as a reactant in the synthesis of a number of compounds. Notably it is used to synthesize 2,3-dimethylbut-2-ene, and is then converted to 2,3-dimethylbutane-2,3-diol and methyl tert-butyl ketone, better known as pinacolone. Pinacolone itself is then used in synthesis for number of pesticides. Additionally, a range of pharmaceuticals, such as butizide, are synthesized from isovaleraldehyde and its corresponding acid. It is a common reagent or building block in organic synthesis.

Acid-catalyzed cyclic trimerization of Isovaleraldehyde gives 2,4,6-Triisobutyl-1,3,5-trioxane [68165-40-2]. This is a flavouring agent that can be used in confectionary, tobacco, and other foodstuffs, toothpastes and the like. It is described as imparting a creamy, dairy, vanilla chocolate and berry flavour.

According to IFF, isovaleraldehyde is used as a food flavorant additive.