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 an odor similar to that of brown sugar. At its boiling point of 171.9 °C, it converts into crotonic acid. The compound can be prepared from 1,3dibromo-
2butanone via the
Favorskii rearrangement
The Favorskii rearrangement is principally a rearrangement of cyclopropanones and α-halo ketones that leads to carboxylic acid derivatives. In the case of cyclic α-halo ketones, the Favorskii rearrangement constitutes a ring contraction. This ...
.
Related compounds
Ethyl isocrotonate can be prepared by
semihydrogenation of
ethyl tetrolate.
Rudolph Fittig and
Hugo Erdmann showed that the γ-phenyl
structural analog
A structural analog, also known as a chemical analog or simply an analog, is a chemical compound, compound having a chemical structure, structure similar to that of another compound, but differing from it in respect to a certain component.
It can ...
of isocrotonic acid forms
α-naphthol
1-Naphthol, or α-naphthol, is an organic compound with the formula . It is a fluorescence, fluorescent white solid. 1-Naphthol differs from its isomer 2-Naphthol, 2-naphthol by the location of the hydroxide, hydroxyl group on the naphthalene rin ...
when
dehydrated
In physiology, dehydration is a lack of total body water that disrupts Metabolism, metabolic processes. It occurs when free water loss exceeds intake, often resulting from excessive sweating, health conditions, or inadequate consumption of wate ...
, an observation that provided useful evidence in understanding the nature of
naphthalene
Naphthalene is an organic compound with formula . It is the simplest polycyclic aromatic hydrocarbon, and is a white Crystal, crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 Parts-per notation ...
.
[{{cite journal, first1 = Rudolph, last1 = Fittig, first2 = Hugo, last2 = Erdmann, authorlink1 = Rudolph Fittig, authorlink2 = Hugo Erdmann, journal = Ber. Dtsch. Chem. Ges., year = 1883, volume = 16, issue = 1, pages = 43–44, language = German, title = Synthese des α-Naphtols, trans-title = Synthesis of α-Naphtol, doi = 10.1002/cber.18830160115, url = https://zenodo.org/record/2452048]
::(''Z'')-(C
6H
5)CH=CHCH
2COOH → α-naphthol + H
2O
References
Enoic acids