Isovaleraldehyde

Isovaleraldehyde
IUPAC name 3-methylbutyraldehyde
Other names Isovaleral, Isovaleric Aldehyde
Identifiers
CAS number	590-86-3
	Properties
Molecular formula	C5H10O
Molar mass	86.13[1]
Appearance	Colorless Liquid[1]
Density	0.785 g/mL at 20 °C[1]
Melting point	−51 °C[1]
Boiling point	92 °C[1]
Solubility in water	Soluble in alcohol and ether, slightly soluble in water[1]
Hazards
Main hazards	Combustible[1]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Isovaleraldehyde is a small organic compound, also known as 3-methylbutanal, with the formula (CH₃)₂CHCH₂CHO. It is an aldehyde, a colorless liquid at STP,^[1] and found in low concentrations in many types of food.^[2] It can be produced commercially and is used as a reagent for the production of pharmaceuticals and pesticides.^[3]

Synthesis

Synthetic routes for the production of isovaleraldehyde vary. One method is by the hydroformylation of isobutene, which forms a small amount of 2,2-dimethylpropanal as a side product.^[3] The balanced reaction is given below

CH₃CH₃CCH₂ + H₂ + CO → (CH₃)₂CHCH₂CHO 95% + (CH₃)₃CCHO 5%

Another method of production involves the isomerization of 3-methyl-3-butene-1-ol using CuO-ZnO as a catalyst. A mixture of 3-methyl-3-butene-1-ol and 3-methyl-2-butene-1-ol may also be used. These starting materials are obtained from a reaction between isobutene and formaldehyde.^[3]

CH₂CH₃CCH₂ + (CH₃)₂CCH₂ + CuO-ZnO (Catalytic Amounts) → (CH₃)₂CHCH₂CHO

Finally, in beer the compound is produced via a reaction between the amino acid leucine and reductones in the malt.^[4]

Occurrences and Uses

As it stems 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 such foods as beer, cheese, coffee, chicken, fish, chocolate, olive oil, and tea.^[2][5]

The compound is used as a reactant in the synthesis of a number of compounds. Notably it is used to synthesize 2,3-dimethyl-2-butene, and is then converted to 2,3-dimethylbutane-2,3-diol and methyltert-butylketone, 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.^[3]

References