Fatty aldehydes are

aliphatic In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated (in which all ...

, long-chain

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 ...

s which may be mono- or polyunsaturated. The fatty aldehydes include compounds such as

octanal Octanal is the organic compound, an aldehyde, with the chemical formula CH3(CH2)6CHO. A colorless fragrant liquid with a fruit-like odor, it occurs naturally in citrus oils. It is used commercially as a component in perfumes and in flavor produ ...

nonanal Nonanal is an organic compound with the chemical formula . It is one of several isomers, all are colorless oil. The nonanals are classified as aldehydes. The linear nonanal is produced commercially by the hydroformylation of 1-octene. It is ...

decanal Decanal is an organic compound with the chemical formula . A colorless oil, it is classified as an aldehyde. Occurrence Decanal occurs naturally in citrus, along with octanal, citral, and sinensal, in buckwheat, and in coriander essential oil ...

or dodecanal. The nomenclature is derived from the nomenclature of the

alkane In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in whi ...

s, the ending ''-al'' is added to indicate the aldehyde group.

Occurrence

Fatty aldehydes are a natural component of many natural ingredients such as the

essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the ...

s of various citrus fruits.

Decanal Decanal is an organic compound with the chemical formula . A colorless oil, it is classified as an aldehyde. Occurrence Decanal occurs naturally in citrus, along with octanal, citral, and sinensal, in buckwheat, and in coriander essential oil ...

, for example, is a component of orange peel. The pheromone cocktails of various insect pheromones contain fatty aldehydes. Fat aldehydes were also detected in the heart muscle of mammals.

Preparation

Fatty aldehydes can be prepared by

dehydrogenation In chemistry, dehydrogenation is a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At ...

fatty alcohol Fatty alcohols (or long-chain alcohols) are usually high-molecular mass, straight-chain primary alcohols, but can also range from as few as 4–6 carbon atoms to as many as 22–26, derived from natural fats and oils. The precise chain length vari ...

s on copper-zinc

catalysts Catalysis () is the increase in reaction rate, rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst ...

. 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 ...

alkene In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The Internationa ...

s, fatty aldehydes are produced on a large industrial scale.

Use

A large proportion of the fatty aldehydes prepared by

is directly processed further to

s. Many fatty aldehydes find use as a

fragrance An aroma compound, also known as an odorant, aroma, fragrance, flavoring or flavor, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficien ...

in perfume production. An example is 2-methylundecanal which is the typical odor component of Chanel No. 5.{{cite web, title=Chemistry in its element - 2-Methylundecanal, url=http://www.rsc.org/chemistryworld/podcast/CIIEcompounds/transcripts/2-methylundecanal.asp, url-status=dead, accessdate=2014-06-20, archiveurl=https://web.archive.org/web/20140528084048/http://www.rsc.org/chemistryworld/podcast/CIIEcompounds/transcripts/2-methylundecanal.asp, archivedate=2014-05-28, language=German

, whose sweet, flowery odor reminiscents of orange peels, is used, among other things, as a

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

in the

food industry The food industry is a complex, global network of diverse businesses that supplies most of the food consumed by the world's population. The food industry today has become highly diversified, with manufacturing ranging from small, traditional, ...

and as a perfume in the perfume industry.

References

Fatty aldehydes Sweet-smelling chemicals

Occurrence

Preparation

Use

See also

References