Isoamyl acetate, also known as isopentyl acetate, is an organic compound that is the ester formed from isoamyl alcohol and

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...

, with the molecular formula C7H14O2.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 which is described as similar to both

banana A banana is an elongated, edible fruit – botanically a berry – produced by several kinds of large herbaceous flowering plants in the genus ''Musa''. In some countries, bananas used for cooking may be called "plantains", distinguis ...

and pear. Pure isoamyl acetate, or mixtures of isoamyl acetate, amyl acetate, and other flavors may be referred to as banana oil.

Production

Isoamyl acetate is prepared by the acid catalyzed reaction (

Fischer esterification Fischer is a German occupational surname, meaning fisherman. The name Fischer is the fourth most common German surname. The English version is Fisher. People with the surname A * Abraham Fischer (1850–1913) South African public official * Ad ...

) between isoamyl alcohol and glacial

as shown in the reaction equation below. Typically,

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...

is used as the catalyst. Alternatively, ''p''-toluenesulfonic acid or an acidic ion exchange resin can be used as the catalyst. :

Applications

Isoamyl acetate is used to confer banana or pear flavor in foods. ''Banana 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

varnish Varnish is a clear transparent hard protective coating or film. It is not a stain. It usually has a yellowish shade from the manufacturing process and materials used, but it may also be pigmented as desired, and is sold commercially in various ...

es and nitrocellulose lacquers. 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 '

aircraft dope Aircraft dope is a plasticised lacquer that is applied to fabric-covered aircraft. It tightens and stiffens fabric stretched over airframes, which renders them airtight and weatherproof, increasing their durability and lifespan.Crane, Dale: '' ...

'. Now that most aircraft wings are made of metal, such use is mostly limited to historically accurate reproductions and scale models. 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

Isoamyl acetate occurs naturally in the

plant and it is also produced synthetically. Isoamyl acetate is released by a honey bee's

sting Sting may refer to: * Stinger or sting, a structure of an animal to inject venom, or the injury produced by a stinger * Irritating hairs or prickles of a stinging plant, or the plant itself Fictional characters and entities * Sting (Middle-eart ...

apparatus where it serves as a pheromone beacon to attract other bees and provoke them to sting.

References

{{DEFAULTSORT:Isoamyl Acetate Flavors Insect pheromones Ester solvents Acetate esters Sweet-smelling chemicals