Isobutyraldehyde is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

with the formula (CH₃)₂CHCHO. It is an

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

, isomeric with ''n''-butyraldehyde (butanal). Isobutyraldehyde is made, often as a side-product, by the

hydroformylation In organic chemistry, hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes () from alkenes (). This chemical reaction entails the net addition of a formyl group () and a hydrogen ...

propene Propylene, also known as propene, is an unsaturated organic compound with the chemical formula . It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like od ...

. Its odour is described as that of wet cereal or straw. It undergoes the

Cannizzaro reaction The Cannizzaro reaction, named after its discoverer Stanislao Cannizzaro, is a chemical reaction which involves the base-induced disproportionation of two molecules of a non-enolizable aldehyde to give a primary alcohol and a carboxylic acid. ...

even though it has alpha hydrogen atom. It is a colorless volatile liquid.

Synthesis

Isobutyraldehyde is produced industrially by the hydroformylation of propene. Several million tons are produced annually.Boy Cornils, Richard W. Fischer, Christian Kohlpaintner "Butanals" in Ullmann's Encyclopedia of Industrial Chemistry, 2000, Wiley-VCH, Weinheim.

Biological routes

In the context of butanol fuel, isobutyraldehyde is of interest as a precursor to

isobutanol Isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol) is an organic compound with the formula (CH3)2CHCH2OH (sometimes represented as ''i''-BuOH). This colorless, flammable liquid with a characteristic smell is mainly used as a solvent either dir ...

. ''E. coli'' as well as several other organisms has been genetically modified to produce isobutanol. α- Ketoisovalerate, derived from oxidative deamination of

valine Valine (symbol Val or V) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α- amino group (which is in the protonated −NH3+ form under biological conditions), an α- carboxylic acid group (which is in the deproton ...

, is prone to

decarboxylation Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is ...

to give isobutyraldehyde, which is susceptible to reduction to the alcohol: :(CH₃)₂CHC(O)CO₂H → (CH₃)₂CHCHO + CO₂ :(CH₃)₂CHCHO + NADH + H⁺ → (CH₃)₂CHCH₂OH + NAD⁺ It can also be produced using engineered bacteria.

Other routes

Strong mineral acids catalyse the rearrangement of methallyl alcohol to isobutyraldehyde.

Reactions

Hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to redox, reduce or Saturated ...

of the aldehyde gives

Oxidation Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

gives methacrolein or

methacrylic acid Methacrylic acid, abbreviated MAA, is an organic compound with the formula CH2=C(CH3)CO2H. This colorless, viscous liquid is a carboxylic acid with an acrid unpleasant odor. It is soluble in warm water and miscible with most organic solvents. Me ...

. Condensation with

formaldehyde Formaldehyde ( , ) (systematic name methanal) is an organic compound with the chemical formula and structure , more precisely . The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as ...

gives hydroxypivaldehyde. The latter is a precursor to vitamin B5. : Pantothenic acid synthesis

References

{{reflist Flavors Alkanals