Allyl alcohol
Encyclopedia
Allyl alcohol is an organic compound
with the structural formula
CH2=CHCH2OH. Like many alcohol
s,it is a water soluble, colourless liquid, but it is more toxic than typical small alcohols. Allyl alcohol is used as a raw material for the production of glycerol, but is used as a precursor to many specialized compounds. Allyl alcohol is the smallest representative of the allyl
ic alcohol
s.
of allyl chloride
is the traditional route:
Allyl alcohol can also be made by the rearrangement of propylene oxide
, a reaction that is catalyzed by potassium alum
at high temperature. The advantage of this method relative to the allyl chloride route is that it does not generate salt. Also avoiding chloride-containing intermediates is the "acetoxylation" of propylene
to allyl acetate
:
Hydrolysis of this acetate gives allyl alcohol. Alternatively, propylene can be oxidized to acrolein
, which upon hydrogenation
gives the alcohol.
of propanol
. In the laboratory, it has been prepared by the reaction of glycerol
and formic acid
. Allyl alcohols in general can be prepared by allylic oxidation of allyl
compounds by selenium dioxide
.
, which is a chemical intermediate in the synthesis of glycerol
, glycidyl ethers, esters and amines. Also, a variety of polymerizable esters are prepared from allyl alcohol, e.g. diallyl phthalate.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
with the structural formula
Structural formula
The structural formula of a chemical compound is a graphical representation of the molecular structure, showing how the atoms are arranged. The chemical bonding within the molecule is also shown, either explicitly or implicitly...
CH2=CHCH2OH. Like many alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s,it is a water soluble, colourless liquid, but it is more toxic than typical small alcohols. Allyl alcohol is used as a raw material for the production of glycerol, but is used as a precursor to many specialized compounds. Allyl alcohol is the smallest representative of the allyl
Allyl
An allyl group is a substituent with the structural formula H2C=CH-CH2R, where R is the connection to the rest of the molecule. It is made up of a methylene , attached to a vinyl group . The name is derived from the Latin word for garlic, Allium sativum. Theodor Wertheim isolated an allyl...
ic alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
s.
Production
Allyl alcohol can be obtained by many methods. The hydrolysisHydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
of allyl chloride
Allyl chloride
Allyl chloride is the organic compound with the formula CH2=CHCH2Cl. This colorless liquid is insoluble in water but soluble in common organic solvents. It is mainly converted to epichlorohydrin, used in the production of plastics. It is a chlorinated derivative of propylene.-Production:Allyl...
is the traditional route:
- CH2CHCH2Cl + NaOH → CH2CHCH2OH + NaCl
Allyl alcohol can also be made by the rearrangement of propylene oxide
Propylene oxide
Propylene oxide is an organic compound with the molecular formula CH3CHCH2O. This colourless volatile liquid is produced on a large scale industrially, its major application being its use for the production of polyether polyols for use in making polyurethane plastics...
, a reaction that is catalyzed by potassium alum
Potassium alum
Potassium alum, potash alum or tawas is the potassium double sulfate of aluminium. Its chemical formula is KAl2 and it is commonly found in its dodecahydrate form as KAl2·12. Alum is the common name for this chemical compound, given the nomenclature of potassium aluminum sulfate dodecahydrate...
at high temperature. The advantage of this method relative to the allyl chloride route is that it does not generate salt. Also avoiding chloride-containing intermediates is the "acetoxylation" of propylene
Propylene
Propene, also known as propylene or methylethylene, is an unsaturated organic compound having the chemical formula C3H6. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons, and it is also second in natural abundance.-Properties:At room temperature and...
to allyl acetate
Allyl acetate
Allyl acetate is an organic compound with formula C3H5OCCH3. This colourless liquid is a precursor to especially allyl alcohol, which is a useful industrial intermediate...
:
- CH2=CHCH3 + 1/2 O2 + CH3CO2H → CH2CHCH2O2CCH3 + H2O
Hydrolysis of this acetate gives allyl alcohol. Alternatively, propylene can be oxidized to acrolein
Acrolein
Acrolein is the simplest unsaturated aldehyde. It is produced widely but is most often immediately reacted with other products due to its instability and toxicity...
, which upon hydrogenation
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...
gives the alcohol.
Other methods
In principle allyl alcohol can be obtained by dehydrogenationDehydrogenation
Dehydrogenation is a chemical reaction that involves the elimination of hydrogen . It is the reverse process of hydrogenation. Dehydrogenation reactions may be either large scale industrial processes or smaller scale laboratory procedures....
of propanol
Propan-1-ol
1-Propanol is a primary alcohol with the molecular formula of C3H8O, and a structural formula of CH3CH2CH2OH. It is also known as propan-1-ol, 1-propyl alcohol, n-propyl alcohol, n-propanol, or simply propanol. It is an isomer of isopropanol . It is used as a solvent in the pharmaceutical...
. In the laboratory, it has been prepared by the reaction of glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
and formic acid
Formic acid
Formic acid is the simplest carboxylic acid. Its chemical formula is HCOOH or HCO2H. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings. In fact, its name comes from the Latin word for ant, formica, referring to its early...
. Allyl alcohols in general can be prepared by allylic oxidation of allyl
Allyl
An allyl group is a substituent with the structural formula H2C=CH-CH2R, where R is the connection to the rest of the molecule. It is made up of a methylene , attached to a vinyl group . The name is derived from the Latin word for garlic, Allium sativum. Theodor Wertheim isolated an allyl...
compounds by selenium dioxide
Selenium dioxide
Selenium dioxide is the chemical compound with the formula SeO2. This colorless solid is one of the most frequently encountered compounds of selenium.-Properties:...
.
Applications
Allyl alcohol is mainly converted to glycidolGlycidol
Glycidol is an organic compound that contains both epoxide and alcohol functional groups. Being bifunctional, it has a variety of industrial uses...
, which is a chemical intermediate in the synthesis of glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
, glycidyl ethers, esters and amines. Also, a variety of polymerizable esters are prepared from allyl alcohol, e.g. diallyl phthalate.