Isoamyl acetate, also known as isopentyl acetate, is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. Th ...

that is the

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

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 componen ...

, 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", disting ...

and

pear Pears are fruits produced and consumed around the world, growing on a tree and harvested in the Northern Hemisphere in late summer into October. The pear tree and shrub are a species of genus ''Pyrus'' , in the Family (biology), family Rosacea ...

. 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) 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 fo ...

is used as the

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

. 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 Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...

that is used as an

artificial flavor A flavoring (or flavouring), also known as flavor (or flavour) or flavorant, is a food additive used to improve the taste or smell of food. It changes the perceptual impression of food as determined primarily by the chemoreceptors of the gus ...

. It is also used as a

solvent A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for ...

for some varnishes and nitrocellulose lacquers. As a solvent and carrier for materials such as

nitrocellulose Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and ...

, 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'. 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-earth ...

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