Esters are a type of molecule usually encountered as sweet smelling organic compounds commonly produced by many plants and fruits. However, the most common esters found in nature are fats and vegetable oils, which are esters of glycerol and fatty acids. In biochemistry, fat is a generic term for a class of lipids. ... A vegetable oil or vegoil is an oil extracted from oilseeds or another plant source. ... ... In chemistry, especially biochemistry, a fatty acid is a carboxylic acid (or organic acid), often with a long aliphatic tail (long chains), either saturated or unsaturated. ...

In organic chemistry and biochemistry esters are substances that have the functional group (R-COO-R') (the carbon is double-bonded to one oxygen atom and single-bonded to another) and consist of an alkane united with the residue of any oxygen acid, organic or inorganic. An ester is a product of the reaction of an acid (usually organic) and an alcohol (the hydrogen of the acid R-COOH is replaced by an alkyl group R"). Esters mainly result from the condensation (this is, a reaction that produces water) of a carboxylic acid and an alcohol. The process is called esterification. This reaction can be catalysed by the presence of H+ ions. Sulphuric acid is often used as a catalyst for this reaction. The name ester is derived from the German Essig-Aether, an old name for acetic acid ethyl ester (ethyl acetate). Organic chemistry is the scientific study of the structure, properties, composition, reactions, and synthesis of organic compounds. ... Biochemistry is the chemistry of life. ... In ecology functional groups are collections of organisms based on morphological, physiological, behavioral, biochemical, or environmental responses or on trophic criteria. ... An alkane in organic chemistry is a type of hydrocarbon in which the molecule has the maximum possible number of hydrogen atoms and so has no double bonds (they are saturated). ... General Name, Symbol, Number Oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16 (VIA), 2, p Density, Hardness 1. ... An acid (often represented by the generic formula AH) is typically a water-soluble, sour-tasting chemical compound. ... An organic acid is an organic compound that is an acid. ... In general usage, alcohol (from Arabic al-khwl الكحول, or al-ghawl الغول) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). ... An alkyl is a functional group of an organic chemical that contains only carbon and hydrogen atoms, which are arranged in a chain. ... A condensation reaction (also known as a dehydration reaction) is a chemical reaction in which two molecules or moieties react with each other with the concurrent loss of water or ammonia. ... Structure of a carboxylic acid Carboxylic acids, also known as alkanoic acids, are organic acids characterized by the presence of a carboxyl group and have the general chemical formula R-C(=O)-OH, also written as R-COOH, where R is a hydrogen or an alkyl group. ... Esterification is the general name for a chemical reaction in that an ester is the reaction product. ... Ethyl acetate, also known as acetic acid ethyl ester, ethyl ethanoate, or acetic ester, is a clear, flammable liquid with a characteristic, not unpleasant smell like certain glues or nail polish removers. ...

This is the general displayed formula of an ester:

Naming of esters

Esters can be produced by an equilibrium reaction between an alcohol and a carboxylic acid. The ester is named according to the alkyl group (the part from the alcohol) and acetate (the part from the carboxylic acid) which make it up; for example, the reaction between methanol and butanoic acid yields the ester methyl butanoate (as well as water). In general usage, alcohol (from Arabic al-khwl الكحول, or al-ghawl الغول) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). ... Structure of a carboxylic acid Carboxylic acids, also known as alkanoic acids, are organic acids characterized by the presence of a carboxyl group and have the general chemical formula R-C(=O)-OH, also written as R-COOH, where R is a hydrogen or an alkyl group. ... An alkyl is a functional group of an organic chemical that contains only carbon and hydrogen atoms, which are arranged in a chain. ... In general usage, alcohol (from Arabic al-khwl الكحول, or al-ghawl الغول) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). ... Acetate, or ethanoate, is the anion of a salt or ester of acetic acid. ... Structure of a carboxylic acid Carboxylic acids, also known as alkanoic acids, are organic acids characterized by the presence of a carboxyl group and have the general chemical formula R-C(=O)-OH, also written as R-COOH, where R is a hydrogen or an alkyl group. ... Methanol, also known as methyl alcohol or wood alcohol, is a chemical compound with chemical formula CH3OH. It is the simplest alcohol, and is a light, volatile, colourless, flammable, poisonous liquid that is used as an antifreeze, solvent, fuel, and as a denaturant for ethyl alcohol. ... n-Butyric acid, IUPAC name n-Butanoic acid, or normal butyric acid, is a carboxylic acid with structural formula CH3CH2CH2_COOH. It is notably found in rancid butter, parmesan cheese, or vomit and has an unpleasant odor and acrid taste, with a sweetish aftertaste (similar to ether). ...

Ethyl ethanoate structure

The simplest ester is H-COO-CH₃ (methyl formate, also called methyl methanoate). The hydrogen atom on the left can be replaced with a CH₃ group or additional CH₂ units, producing other methyl esters, including methyl stearate, a component of biodiesel. Methyl formate, also called methyl methanoate, is the methyl ester of formic acid. ... Bus running on soybean biodiesel. ...

Physical properties

Esters can participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding makes them more water soluble than their parent hydrocarbons. But the limitations on their hydrogen bonding also make them more hydrophobic than either their parent alcohols or parent acids. Their lack of hydrogen bond donating ability means that they cannot form hydrogen bonds between ester molecules, which makes them generally more volatile than an carboxylic acid of similar molecular weight. This property makes them very useful in organic analytical chemistry. Unknown organic acids with low volatility can often be esterified into a volatile ester which can then be analysed using gas chromatography, gas liquid chromatography, or mass spectrometry. In chemistry, a hydrogen bond is a type of attractive intermolecular force that exists between two partial electric charges of opposite polarity. ... A falling water droplet Water (from the Anglo-Saxon and Low German wæter) is a colourless, tasteless, and odourless substance that is essential to all known forms of life and is the most universal solvent. ... A substance is soluble in a fluid if it dissolves in the fluid. ... In chemistry, a hydrocarbon is a group of chemical compounds consisting only of carbon (C) and hydrogen (H). ... In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... Structure of a carboxylic acid Carboxylic acids, also known as alkanoic acids, are organic acids characterized by the presence of a carboxyl group and have the general chemical formula R-C(=O)-OH, also written as R-COOH, where R is a hydrogen or an alkyl group. ... Gas-liquid chromatography (GLC), or simply gas chromatography (GC) is a type of chromatography in which the mobile phase is a carrier gas, usually an inert gas such as helium or nitrogen, and the stationary phase is a microscopic layer of liquid on an inert solid support. ... Mass spectrometry is a technique for separating ions by their mass-to-charge (m/z) ratios. ...

Many esters have distinctive odors, which has led to their widespread use as artificial flavorings and fragrances. For example:

methyl butanoate smells of pineapple

methyl salicylate (oil of wintergreen) smells of the ointments called Germolene™ and Ralgex™ in the UK

methyl benzoate smells of marzipan

ethyl methanoate smells of raspberry

ethyl butanoate smells of pineapple

pentyl ethanoate smells of banana

pentyl pentanoate smells of apple

pentyl butanoate smells of pear or apricot

octyl ethanoate smells of orange

Esters may undergo hydrolysis - the breakdown of an ester by water. This process can be catalyzed both by acids and bases. The base catalyzed process is called saponification. The hydrolysis yields an alcohol and a carboxylic acid or its respective carboxylate salt. Binomial name Ananas comosus The pineapple (Ananas comosus) is a tropical plant and its fruit, native to Brazil, Bolivia, and Paraguay. ... Methyl salicylate (chemical formula C6H4(HO)COOCH3; also known as oil of wintergreen, betula oil, methyl ester) is a natural product of many species of plants. ... Wintergreen was originally a term referring to a plant that continues photosynthesis (i. ... This article is about the food marzipan; for the Homestar Runner character of this name, see: Marzipan (character). ... For the sound made by humans to simulate flatulence (blowing a raspberry) see the USA term, Bronx cheer Species Rubus idaeus raspberry (red) - watercolor 1892 The Raspberry or Red Raspberry, (Rubus idaeus) is a plant that produces a tart, sweet, red composite fruit (not a true berry) in late summer... Ethyl butanoate is an ester with the chemical formula CH3-CH2-CH2-COO-CH2-CH3, with one oxygen having a double bond. ... Binomial name Ananas comosus The pineapple (Ananas comosus) is a tropical plant and its fruit, native to Brazil, Bolivia, and Paraguay. ... Species Hybrid origin; see text A banana is a tree-like plant (though strictly a herb) of the genus Musa in the family Musaceae, closely related to plantains. ... Species Malus domestica Malus sieversii The apple is the pomaceous fruit of trees of the genus Malus in the family Rosaceae, and is one of the most widely cultivated tree fruits. ... The ester formed when Pentanol is reacted with Butyric acid; usually in the prescence of sulfuric acid as a catalyst. ... Species Pyrus calleryana P. pyrifolia et al Pears are trees of the genus Pyrus and the edible fruit of that tree. ... Binomial name Prunus armeniaca The scientific name for the apricot is Prunus armeniaca L., which puts it in the same subgenus as the plum (Prunophora). ... Orange blossoms and oranges on tree For other uses of orange, see orange (disambiguation) The Orange Citrus x sinensis is a Citrus tree, and the fruits of this tree. ... Hydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. ... Saponification is the hydrolysis of an ester under basic conditions to form an alcohol and the salt of the acid. ... Structure of a carboxylic acid Carboxylic acids, also known as alkanoic acids, are organic acids characterized by the presence of a carboxyl group and have the general chemical formula R-C(=O)-OH, also written as R-COOH, where R is a hydrogen or an alkyl group. ... For other meanings of the word salt see table salt or salt (disambiguation). ...

Esters are able to react with alchohol for form another ester and water. For instance, CH3CH2COOH + CH3OH yields CH3CH2COOCH3 and H2O

Ester saponification (basic hydrolysis)

See also

• Polyester

Close-up of a polyester shirt SEM picture of a bend in a high surface area polyester fiber with a seven-lobed cross section Polyester is a category of polymers which contain the ester functional group in their main chain. ...

External links

• Molecule of the month: Ethyl acetate and other esters (http://www.chm.bris.ac.uk/motm/ethylacetate/ethylh.htm)