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In chemistry, an ester is a compound derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group (−OH) of that acid is replaced by an organyl group (−R). Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well (i.e. esters of acidic −SH, −SeH, −TeH, −PoH and −LvH groups). According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well (e.g. amides), but not according to the IUPAC. [1]
An example of an ester formation is the substitution reaction between a carboxylic acid (R−C(=O)−OH) and an alcohol (R'OH), forming an ester (R−C(=O)−O−R'), where R and R′ are organyl groups, or H in the case of esters of formic acid. Glycerides, which are fatty acid esters of glycerol, are important esters in biology, being one of the main classes of lipids, and making up the bulk of animal fats and vegetable oils. Esters of carboxylic acids with low molecular weight are commonly used as fragrances and found in essential oils and pheromones. Phosphoesters form the backbone of DNA molecules. Nitrate esters, such as nitroglycerin, are known for their explosive properties, while polyesters are important plastics, with monomers linked by ester moieties. Esters of carboxylic acids usually have a sweet smell and are considered high-quality solvents for a broad array of plastics, plasticizers, resins, and lacquers. [2] They are also one of the largest classes of synthetic lubricants on the commercial market. [3]
Name | Structure |
---|---|
Propyl acetate | |
Propyl propanoate | |
Propyl hexanoate | |
Allyl hexanoate | |
Isopropyl acetate | |
Isopropyl salicylate | |
Isopropyl palmitate |
Name | Structure |
---|---|
Butyl formate | |
Butyl acetate | |
Isobutyl formate | |
Isobutyl acetate | |
Sec-Butyl formate | |
Sec-Butyl acetate | |
Tert-Butyl formate | |
Tert-Butyl acetate | |
Butyl butyrate |
Name | Structure |
---|---|
Amyl acetate | |
Pentyl butyrate | |
Pentyl propanoate | |
Pentyl hexanoate | |
Sec-Amyl acetate |
Name | Structure |
---|---|
Benzyl acetate |
Name | Structure |
---|---|
Octyl acetate |
Name | Structure |
---|---|
Geranyl acetate | |
Bornyl acetate | |
Linalyl acetate |
Name | Structure |
---|---|
Methyl nitrate |
Name | Structure |
---|---|
Methyl formate | |
Ethyl formate | |
Isobutyl formate |
Name | Structure |
---|---|
Methyl acetate | |
Ethyl acetate | |
Propyl acetate | |
Butyl acetate | |
Amyl acetate | |
Benzyl acetate | |
Octyl acetate | |
Geranyl acetate | |
Bornyl acetate | |
Linalyl acetate |
Name | Structure |
---|---|
Methyl propionate | |
Ethyl propionate | |
Propyl propanoate | |
Pentyl propanoate | |
Ethyl lactate |
Name | Structure |
---|---|
Methyl butyrate | |
Ethyl butyrate | |
Butyl butyrate | |
Pentyl butyrate |
Name | Structure |
---|---|
Methyl pentanoate | |
Ethyl pentanoate | |
Pentyl pentanoate | |
Ethyl isovalerate |
Name | Structure |
---|---|
Ethyl hexanoate | |
Propyl hexanoate | |
Allyl hexanoate | |
Pentyl hexanoate |
Name | Structure |
---|---|
Ethyl heptanoate | |
Methyl benzoate | |
Ethyl benzoate | |
Methyl anthranilate | |
Methyl salicylate | |
Ethyl salicylate | |
Isopropyl salicylate |
Name | Structure |
---|---|
Ethyl octanoate | |
Methyl phenylacetate |
Name | Structure |
---|---|
Methyl cinnamate | |
Ethyl cinnamate |
Name | Structure |
---|---|
Ethyl decanoate |
Name | Structure |
---|---|
Isopropyl palmitate |
Many esters of carboxylic acid have distinctive fruit-like odors, and many occur naturally in fruits and the essential oils of plants. This has also led to their common use in artificial flavorings and fragrances which aim to mimic those odors.
Lactones are a specific class cyclic carboxylic esters that are formed through intramolecular esterification.
Lactone name | Structure |
---|---|
β-propiolactone | |
γ-butyrolactone (GBL) | |
D-glucono-δ-lactone (E575) | |
ε-caprolactone |
In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is often written as R−COOH or R−CO2H, sometimes as R−C(O)OH with R referring to an organyl group, or hydrogen, or other groups. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion.
In chemistry, an ester is a functional group derived from an acid in which the hydrogen atom (H) of at least one acidic hydroxyl group of that acid is replaced by an organyl group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well, but not according to the IUPAC.
An acetate is a salt formed by the combination of acetic acid with a base. "Acetate" also describes the conjugate base or ion typically found in aqueous solution and written with the chemical formula C
2H
3O−
2. The neutral molecules formed by the combination of the acetate ion and a positive ion are also commonly called "acetates". The simplest of these is hydrogen acetate with corresponding salts, esters, and the polyatomic anion CH
3CO−
2, or CH
3COO−
.
In chemical nomenclature, the IUPAC nomenclature of organic chemistry is a method of naming organic chemical compounds as recommended by the International Union of Pure and Applied Chemistry (IUPAC). It is published in the Nomenclature of Organic Chemistry. Ideally, every possible organic compound should have a name from which an unambiguous structural formula can be created. There is also an IUPAC nomenclature of inorganic chemistry.
Ethyl butyrate, also known as ethyl butanoate, or butyric ether, is an ester with the chemical formula CH3CH2CH2COOCH2CH3. It is soluble in propylene glycol, paraffin oil, and kerosene. It has a fruity odor, similar to pineapple, and is a key ingredient used as a flavor enhancer in processed orange juices. It also occurs naturally in many fruits, albeit at lower concentrations.
Cinnamic acid is an organic compound with the formula C6H5-CH=CH-COOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs naturally in a number of plants. It exists as both a cis and a trans isomer, although the latter is more common.
Valeric acid or pentanoic acid is a straight-chain alkyl carboxylic acid with the chemical formula CH3(CH2)3COOH. Like other low-molecular-weight carboxylic acids, it has an unpleasant odor. It is found in the perennial flowering plant Valeriana officinalis, from which it gets its name. Its primary use is in the synthesis of its esters. Salts and esters of valeric acid are known as valerates or pentanoates. Volatile esters of valeric acid tend to have pleasant odors and are used in perfumes and cosmetics. Several, including ethyl valerate and pentyl valerate are used as food additives because of their fruity flavors.
Methyl butyrate, also known under the systematic name methyl butanoate, is the methyl ester of butyric acid. Like most esters, it has a fruity odor, in this case resembling apples or pineapples. At room temperature, it is a colorless liquid with low solubility in water, upon which it floats to form an oily layer. Although it is flammable, it has a relatively low vapor pressure, so it can be safely handled at room temperature without special safety precautions.
In chemistry, solvolysis is a type of nucleophilic substitution (SN1/SN2) or elimination where the nucleophile is a solvent molecule. Characteristic of SN1 reactions, solvolysis of a chiral reactant affords the racemate. Sometimes however, the stereochemical course is complicated by intimate ion pairs, whereby the leaving anion remains close to the carbocation, effectively shielding it from an attack by the nucleophile. Particularly fast reactions can occur by neighbour group participation, with nonclassical ions as intermediates or transition states.
A xanthate is a salt or ester of a xanthic acid. The formula of the salt of xanthic acid is [R−O−CS2]−M+. Xanthate also refers to the anion [R−O−CS2]−. The formula of a xanthic acid is R−O−C(=S)−S−H, such as ethyl xanthic acid, while the formula of an ester of a xanthic acid is R−O−C(=S)−S−R', where R and R' are organyl groups. The salts of xanthates are also called O-organyl dithioates. The esters of xanthic acid are also called O,S-diorganyl esters of dithiocarbonic acid. The name xanthate is derived from Ancient Greek ξανθός (xanthos) meaning 'yellowish' or 'golden', and indeed most xanthate salts are yellow. They were discovered and named in 1823 by Danish chemist William Christopher Zeise. These organosulfur compounds are important in two areas: the production of cellophane and related polymers from cellulose and for extraction of certain sulphide bearing ores. They are also versatile intermediates in organic synthesis.
Methyl benzoate is an organic compound. It is an ester with the chemical formula C6H5COOCH3, sometimes abbreviated as PhCO2Me, where Ph and Me are phenyl and methyl, respectively. Its structure is C6H5−C(=O)−O−CH3. It is a colorless liquid that is poorly soluble in water, but miscible with organic solvents. Methyl benzoate has a pleasant smell, strongly reminiscent of the fruit of the feijoa tree, and it is used in perfumery. It also finds use as a solvent and as a pesticide used to attract insects such as orchid bees.
Propiolic acid is the organic compound with the formula HC2CO2H. It is the simplest acetylenic carboxylic acid. It is a colourless liquid that crystallises to give silky crystals. Near its boiling point, it decomposes.
Enanthic acid, also called heptanoic acid, is an organic compound composed of a seven-carbon chain terminating in a carboxylic acid functional group. It is a colorless oily liquid with an unpleasant, rancid odor. It contributes to the odor of some rancid oils. It is slightly soluble in water, but very soluble in ethanol and ether. Salts and esters of enanthic acid are called enanthates or heptanoates.
Butamben is a local anesthetic. Proprietary names includes Alvogil in Spain and Alvogyl in Switzerland. It is one of three components in the topical anesthetic Cetacaine.
Ethyl benzoate, C9H10O2, is an ester formed by the condensation of benzoic acid and ethanol. It is a colorless liquid that is almost insoluble in water, but miscible with most organic solvents.
Methyl pentanoate, commonly known as methyl valerate, is the methyl ester of pentanoic acid with a fruity odor.
The suffix -oate is the IUPAC nomenclature used in organic chemistry to form names of compounds formed from carboxylic acids. They are of two types:
Pentenoic acid is any of five mono-carboxylic acids whose molecule has an unbranched chain of five carbons connected by three single bonds and one double bond. That is, any compound with one of the formulas HO(O=)C−CH=CH−CH2−CH3 (2-pentenoic), HO(O=)C−CH2−CH=CH−CH3 (3-pentenoic), or HO(O=)C−CH2−CH2−CH=CH2 (4-pentenoic). In the IUPAC-recommended nomenclature, these acids are called pent-2-enoic, pent-3-enoic, and pent-4-enoic, respectively. All these compounds have the empirical formula C
5H
8O
2.