Butenoic acid is any of three mono
carboxylic acids with an unbranched 4-carbon chain with 3
single bonds and one
double bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betwee ...
; that is, with the structural formula –––H (2-butenoic) or –––H (3-butenoic). All have the chemical formula or .
These compounds are technically mono-unsaturated
fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...
s, although some authors may exclude them for being too short. The three isomers are:
*
crotonic acid
Crotonic acid ((2''E'')-but-2-enoic acid) is a short-chain unsaturated carboxylic acid, described by the formula CH3CH=CHCO2H. It is called crotonic acid because it was erroneously thought to be a saponification product of croton oil. It crysta ...
(''trans''-2-butenoic or (2''E'')-but-2-enoic acid)
*
isocrotonic acid
Isocrotonic acid (also known as quartenylic acid; formally named (''Z'')-2-butenoic acid) is the ''cis'' isomer of crotonic acid. It is an oil, possessing a smell similar to that of brown sugar. It boils at 171.9 °C, concomitant with co ...
(''cis''-2-butenoic or (2''Z'')-but-2-enoic acid)
*
3-butenoic acid (but-3-enoic acid).
[
]
See also
*Methacrylic acid
Methacrylic acid, abbreviated MAA, is an organic compound. This colorless, viscous liquid is a carboxylic acid with an acrid unpleasant odor. It is soluble in warm water and miscible with most organic solvents. Methacrylic acid is produced indu ...
, also but branched like isobutene; a.k.a. isobutenoic acid
* Butyric acid, ; a.k.a. butanoic acid
References
Carboxylic acids
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