Crotonaldehyde
Encyclopedia
Crotonaldehyde is a chemical compound
with the formula
CH3CH=CHCHO. The compound is usually sold as a mixture of the E- and Z-isomers, which differ with respect to the relative position of the methyl and formyl groups. The E-isomer is more common (data given in Table is for the E-isomer). This lachrymatory liquid is moderately soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is a versatile intermediate in organic synthesis
. It occurs in a variety of foodstuffs, e.g. soybean oil
s.
of acetaldehyde
:
Its main application is as a precursor to fine chemicals. Sorbic acid
, a food preservative, and trimethylhydroquinone, a precursor to the vitamin E, are prepared from crotonaldehyde. Other derivatives include crotonic acid and 3-methoxybutanol.
Crotonaldehyde is a multifunctional molecule that exhibits diverse reactivity. It is an excellent prochiral
dienophile. It is a Michael acceptor. Addition of methylmagnesium chloride
affords 3-penten-2-ol.
. It occurs widely in nature.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
CH3CH=CHCHO. The compound is usually sold as a mixture of the E- and Z-isomers, which differ with respect to the relative position of the methyl and formyl groups. The E-isomer is more common (data given in Table is for the E-isomer). This lachrymatory liquid is moderately soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is a versatile intermediate in organic synthesis
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...
. It occurs in a variety of foodstuffs, e.g. soybean oil
Soybean oil
Soybean oil is a vegetable oil extracted from the seeds of the soybean . It is one of the most widely consumed cooking oils. As a drying oil, processed soybean oil is also used as a base for printing inks and oil paints...
s.
Production and uses
Crotonaldehyde is produced by the aldol condensationAldol condensation
An aldol condensation is an organic reaction in which an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone, followed by a dehydration to give a conjugated enone....
of acetaldehyde
Acetaldehyde
Acetaldehyde is an organic chemical compound with the formula CH3CHO or MeCHO. It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale industrially. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, and is produced by plants as part...
:
- 2 CH3CHO → CH3CH=CHCHO + H2O
Its main application is as a precursor to fine chemicals. Sorbic acid
Sorbic acid
Sorbic acid, or 2,4-hexadienoic acid, is a natural organic compound used as a food preservative. It has the chemical formula C6H8O2. It is a colourless solid that is slightly soluble in water and sublimes readily...
, a food preservative, and trimethylhydroquinone, a precursor to the vitamin E, are prepared from crotonaldehyde. Other derivatives include crotonic acid and 3-methoxybutanol.
Crotonaldehyde is a multifunctional molecule that exhibits diverse reactivity. It is an excellent prochiral
Prochiral
In stereochemistry, prochiral molecules are those that can be converted from achiral to chiral in a single step.If two identical substituents are attached to a sp3-hybridized atom, the descriptors pro-R and pro-S are used to distinguish between the two...
dienophile. It is a Michael acceptor. Addition of methylmagnesium chloride
Methylmagnesium chloride
Methylmagnesium chloride is a commercially available Grignard reagent. Like methyllithium, it is the synthetic equivalent to the methyl carbanion synthon. It is usually sold as a solution in tetrahydrofuran. The model of the molecule shows methylmagnesium chloride with the magnesium atom in the...
affords 3-penten-2-ol.
Safety
Crotonaldehyde is an irritant. It is listed as an "extremely hazardous substance" as defined by the U.S. Emergency Planning and Community Right-to-Know ActEmergency Planning and Community Right-to-Know Act
The Emergency Planning and Community Right-to-Know Act of 1986 is a United States federal law passed by the 99th United States Congress located at Title 42, Chapter 116 of the U.S. Code, concerned with emergency response preparedness....
. It occurs widely in nature.