Isopentyl acetate

Isoamyl acetate
Identifiers
CAS number 123-92-2 YesY
ChemSpider 29016 YesY
UNII Z135787824 YesY
KEGG C12296 YesY
ChEBI CHEBI:31725 YesY
Jmol-3D images Image 1
Properties
Molecular formula C7H14O2
Molar mass 130.19 g/mol
Appearance colorless liquid
Odor banana-like [1]
Density 0.876 g/cm3
Melting point

−78 °C, 195 K, -108 °F

Boiling point

142 °C, 415 K, 288 °F

Hazards
NFPA 704
3
1
0
Flash point 25 °C
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Isoamyl acetate, also known as isopentyl acetate, is an organic compound that is the ester formed from isoamyl alcohol and acetic acid. It is a colorless liquid that is only slightly soluble in water, but very soluble in most organic solvents. Isoamyl acetate has a strong odor (similar to Juicy Fruit, a foam banana sweet or a pear drop) which is also described as similar to both banana and pear. Banana oil is a term that is applied either to pure isoamyl acetate or to flavorings that are mixtures of isoamyl acetate, amyl acetate, and other flavors.[2]

Production

Isoamyl acetate is prepared by the acid catalyzed reaction (Fischer esterification) between isoamyl alcohol and glacial acetic acid as shown in the reaction equation below. Typically, sulfuric acid is used as the catalyst. Alternately, an acidic ion exchange resin can be used as the catalyst.

Applications

Isoamyl acetate is used to confer banana flavor in foods. Pear oil commonly refers to a solution of isoamyl acetate in ethanol that is used as an artificial flavor.

It is also used as a solvent for some varnishes and nitrocellulose lacquers, as well as being a honey bee pheromone and can be used to attract large groups of honeybees to a small area. As a solvent and carrier for materials such as nitrocellulose, it was extensively used in the aircraft industry for stiffening and wind-proofing fabric flying surfaces, where it and its derivatives were generally known as 'dope'. Now that most aircraft are all-metal, such use is now limited to model aircraft, where it is still popularly used for strengthening tissue coverings and balsa wood.

Because of its intense, pleasant odor and its low toxicity, isoamyl acetate is used to test the effectiveness of respirators or gas masks.

Occurrence in nature

Banana oil is made naturally by the banana plant;[3] it is also produced synthetically.[4]

Isoamyl acetate is released by a honey bee's sting apparatus where it serves as a pheromone beacon to attract other bees and provoke them to sting.[5]

References