Phenethyl alcohol
Encyclopedia
Phenethyl alcohol, or 2-phenylethanol, is the organic compound
with the formula
C6H5CH2CH2OH. This colourless liquid occurs widely in nature, being found in a variety of essential oil
s, including rose
, carnation, hyacinth, Aleppo pine
, orange blossom
, ylang-ylang
, geranium
, neroli
, and champaca. It is slightly soluble in water (2 mL/100 mL H2O), but miscible with ethanol
and ether
.
Phenethyl alcohol is an alcohol
with a pleasant floral odor. It is therefore a common ingredient in flavors and perfumery, particularly when the smell of rose is desired. It is used as an additive in cigarettes. It is also used as a preservative
in soap
s due to its stability in basic conditions. In biology
it is of interest due to its antimicrobial
properties.
between phenylmagnesium bromide
and ethylene oxide
:
However, the Friedel-Crafts reaction between benzene
and ethylene oxide may also be employed:
Phenethyl alcohol can also be prepared also by biotransformation from L-phenylalanine
using immobilized yeast Saccharomyces cerevisiae
.
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 formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
C6H5CH2CH2OH. This colourless liquid occurs widely in nature, being found in a variety of essential oil
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
s, including rose
Rose oil
Rose oil, meaning either rose otto or rose absolute, is the essential oil extracted from the petals of various types of rose...
, carnation, hyacinth, Aleppo pine
Aleppo Pine
Pinus halepensis, commonly known as the Aleppo Pine, is a pine native to the Mediterranean region. Their range extends from Morocco and Spain north to southern France, Italy and Croatia, and east to Greece and northern Tunisia, and Libya, with an outlying population in Syria, Lebanon, southern...
, orange blossom
Orange (fruit)
An orange—specifically, the sweet orange—is the citrus Citrus × sinensis and its fruit. It is the most commonly grown tree fruit in the world....
, ylang-ylang
Ylang-ylang
Cananga odorata, commonly called Ylang-ylang , cananga tree, ilang-ilang, kenanga , fragrant cananga, Macassar-oil plant or perfume tree),is a tree valued for its perfume...
, geranium
Pelargonium
Pelargonium is a genus of flowering plants which includes about 200 species of perennials, succulents, and shrubs, commonly known as scented geraniums or storksbills. Confusingly, Geranium is the correct botanical name of a separate genus of related plants often called Cranesbills. Both Geranium...
, neroli
Neroli
Neroli oil is a plant oil produced from the blossom of the bitter orange tree . Its scent is sweet, honeyed and somewhat metallic, whereas bergamot, being rich in linalool , has more of an aromatic, soft, floralcy.- Production :The blossoms are gathered, usually by hand, in late April to...
, and champaca. It is slightly soluble in water (2 mL/100 mL H2O), but miscible with ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
and ether
Diethyl ether
Diethyl ether, also known as ethyl ether, simply ether, or ethoxyethane, is an organic compound in the ether class with the formula . It is a colorless, highly volatile flammable liquid with a characteristic odor...
.
Phenethyl alcohol is an 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....
with a pleasant floral odor. It is therefore a common ingredient in flavors and perfumery, particularly when the smell of rose is desired. It is used as an additive in cigarettes. It is also used as a preservative
Preservative
A preservative is a naturally occurring or synthetically produced substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by microbial growth or by undesirable chemical changes....
in soap
Soap
In chemistry, soap is a salt of a fatty acid.IUPAC. "" Compendium of Chemical Terminology, 2nd ed. . Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford . XML on-line corrected version: created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN...
s due to its stability in basic conditions. In biology
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
it is of interest due to its antimicrobial
Antimicrobial
An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...
properties.
Synthesis
Phenethyl alcohol can be prepared by a variety of procedures, such as by a Grignard reactionGrignard reaction
The Grignard reaction is an organometallic chemical reaction in which alkyl- or aryl-magnesium halides add to a carbonyl group in an aldehyde or ketone. This reaction is an important tool for the formation of carbon–carbon bonds...
between phenylmagnesium bromide
Phenylmagnesium bromide
Phenylmagnesium bromide, with the simplified formula , is a magnesium-containing organometallic compound. It is so commonly used that it is commercially available as a solution in diethyl ether or tetrahydrofuran . Phenylmagnesium bromide is a Grignard reagent...
and ethylene oxide
Ethylene oxide
Ethylene oxide, also called oxirane, is the organic compound with the formula . It is a cyclic ether. This means that it is composed of two alkyl groups attached to an oxygen atom in a cyclic shape . This colorless flammable gas with a faintly sweet odor is the simplest epoxide, a three-membered...
:
- C6H5MgBr + CH2CH2O → C6H5CH2CH2OMgBr
- C6H5CH2CH2OMgBr + H+ → C6H5CH2CH2OH
However, the Friedel-Crafts reaction between benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
and ethylene oxide may also be employed:
- C6H6 + CH2CH2O (+ AlCl3) → C6H5CH2CH2OH (+AlCl3)
Phenethyl alcohol can also be prepared also by biotransformation from L-phenylalanine
Phenylalanine
Phenylalanine is an α-amino acid with the formula C6H5CH2CHCOOH. This essential amino acid is classified as nonpolar because of the hydrophobic nature of the benzyl side chain. L-Phenylalanine is an electrically neutral amino acid, one of the twenty common amino acids used to biochemically form...
using immobilized yeast Saccharomyces cerevisiae
Saccharomyces cerevisiae
Saccharomyces cerevisiae is a species of yeast. It is perhaps the most useful yeast, having been instrumental to baking and brewing since ancient times. It is believed that it was originally isolated from the skin of grapes...
.