In chemistry, an ester is a compound 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.
Ethyl carbamate (also called urethane) is an organic compound with the formula CH3CH2OC(O)NH2. It is an ester of carbamic acid and a white solid. Despite its name, it is not a component of polyurethanes. Because it is a carcinogen, it is rarely used, but naturally forms in low quantities in many types of fermented foods and drinks.
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.
Isobutyric acid, also known as 2-methylpropanoic acid or isobutanoic acid, is a carboxylic acid with structural formula (CH3)2CHCOOH. It is an isomer of butyric acid. It is classified as a short-chain fatty acid. Deprotonation or esterification gives derivatives called isobutyrates.
Ethyl oleate is a fatty acid ester formed by the condensation of oleic acid and ethanol. It is a colorless oil although degraded samples can appear yellow.
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 methacrylate (MMA) is an organic compound with the formula CH2=C(CH3)COOCH3. This colorless liquid, the methyl ester of methacrylic acid (MAA), is a monomer produced on a large scale for the production of poly(methyl methacrylate) (PMMA).
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.
Dimethyl sulfate (DMS) is a chemical compound with formula (CH3O)2SO2. As the diester of methanol and sulfuric acid, its formula is often written as (CH3)2SO4 or Me2SO4, where CH3 or Me is methyl. Me2SO4 is mainly used as a methylating agent in organic synthesis.
Caproic acid, also known as hexanoic acid, is the carboxylic acid derived from hexane with the chemical formula CH3(CH2)4COOH. It is a colorless oily liquid with an odor that is fatty, cheesy, waxy, and like that of goats or other barnyard animals. It is a fatty acid found naturally in various animal fats and oils, and is one of the chemicals that gives the decomposing fleshy seed coat of the ginkgo its characteristic unpleasant odor. It is also one of the components of vanilla and cheese. The primary use of caproic acid is in the manufacture of its esters for use as artificial flavors, and in the manufacture of hexyl derivatives, such as hexylphenols. Salts and esters of caproic acid are known as caproates or hexanoates. Several progestin medications are caproate esters, such as hydroxyprogesterone caproate and gestonorone caproate.
3-Methylbutanoic acid, also known as β-methylbutyric acid or more commonly isovaleric acid, is a branched-chain alkyl carboxylic acid with the chemical formula (CH3)2CHCH2CO2H. It is classified as a short-chain fatty acid. Like other low-molecular-weight carboxylic acids, it has an unpleasant odor. The compound occurs naturally and can be found in many foods, such as cheese, soy milk, and apple juice.
Methyl chloroformate is a chemical compound with the chemical formula Cl−C(=O)−O−CH3. It is the methyl ester of chloroformic acid. It is an oily colorless liquid, although aged samples appear yellow. It is also known for its pungent odor.
Propyl hexanoate (C9H18O2), also known as propyl caproate, is an ester formed by the reaction of propanol with hexanoic acid. Although it is a completely different ester, propyl hexanoate shares the same chemical formula with methyl octanoate, ethyl heptanoate, butyl pentanoate, etc. because they all have the same total carbon chain length. The scent of this ester can be described as that of blackberries, pineapple, cheese or wine.
4-Methylcyclohexanemethanol (MCHM, systematic name 4-methylcyclohexylmethanol) is an organic compound with the formula CH3C6H10CH2OH. Classified as a saturated higher alicyclic primary alcohol. Both cis and trans isomers exist, depending on the relative positions of the methyl (CH3) and hydroxymethyl (CH2OH) groups on the cyclohexane ring. Commercial samples of MCHM consists of a mixture of these isomers as well as other components that vary with the supplier.
Ethyl octanoate, also known as ethyl caprylate, is a fatty acid ester formed from caprylic acid and ethanol. A colorless liquid at room temperature, it has the semi-developed formula of CH3(CH2)6COOCH2CH3, and is used in food industries as a flavoring and in the perfume industry as a scent additive. It is present in many fruits and alcoholic beverages, and has a strong odor of fruit and flowers. It is used in the creation of synthetic fruity scents.
Cinnamyl acetate is a chemical compound of the cinnamyl ester family, in which the variable R group is substituted by a methyl group. As a result of the non-aromatic carbon-carbon double bond, cinnamyl acetate can exist in a Z and an E configuration:
Dimethylaminoethyl acrylate or DMAEA is an unsaturated carboxylic acid ester having a tertiary amino group. It is a colorless to yellowish, water-miscible liquid with a pungent, amine-like odor. DMAEA is an important acrylic monomer that gives basic properties to copolymers.
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.
