Geraniol

Last updated
Geraniol [1]
Geraniol structure.png
Geraniol-3D-balls-B.png
Names
Preferred IUPAC name
(2E)-3,7-Dimethylocta-2,6-dien-1-ol
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.003.071 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 203-377-1
KEGG
PubChem CID
UNII
  • InChI=1S/C10H18O/c1-9(2)5-4-6-10(3)7-8-11/h5,7,11H,4,6,8H2,1-3H3/b10-7+ Yes check.svgY
    Key: GLZPCOQZEFWAFX-JXMROGBWSA-N Yes check.svgY
  • InChI=1/C10H18O/c1-9(2)5-4-6-10(3)7-8-11/h5,7,11H,4,6,8H2,1-3H3/b10-7+
    Key: GLZPCOQZEFWAFX-JXMROGBWBZ
  • CC(=CCC/C(=C/CO)/C)C
Properties
C10H18O
Molar mass 154.253 g·mol−1
Density 0.889 g/cm3
Melting point −15 °C (5 °F; 258 K) [2]
Boiling point 230 °C (446 °F; 503 K) [2]
686 mg/L (20 °C) [2]
log P 3.28 [3]
Hazards
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
1
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Geraniol is a monoterpenoid and an alcohol. It is the primary component of citronella oil and is a primary component of rose oil, palmarosa oil. It is a colorless oil, although commercial samples can appear yellow. It has low solubility in water, but it is soluble in common organic solvents. The functional group derived from geraniol (in essence, geraniol lacking the terminal −OH) is called geranyl.

Contents

Uses and occurrence

In addition to rose oil, palmarosa oil, and citronella oil, it also occurs in small quantities in geranium, lemon, and many other essential oils. With a rose-like scent, it is commonly used in perfumes. It is used in scents such as peach, raspberry, grapefruit, red apple, plum, lime, orange, lemon, watermelon, pineapple, and blueberry.

Geraniol is produced by the scent glands of honeybees to mark nectar-bearing flowers and locate the entrances to their hives. [5] It is also commonly used as an insect repellent, especially for mosquitoes. [6]

The scent of geraniol is reminiscent of, but chemically unrelated to, 2-ethoxy-3,5-hexadiene, also known as geranium taint, a wine fault resulting from fermentation of sorbic acid by lactic acid bacteria. [7]

Geranyl pyrophosphate is important in biosynthesis of other terpenes such as myrcene and ocimene. [8] It is also used in the biosynthesis pathway of many cannabinoids in the form of CBGA. [9]

Reactions

In acidic solutions, geraniol is converted to the cyclic terpene α-terpineol. The alcohol group undergoes expected reactions. It can be converted to the tosylate, which is a precursor to the chloride. Geranyl chloride also arises by the Appel reaction by treating geraniol with triphenylphosphine and carbon tetrachloride. [10] [11] It can be hydrogenated. [12] It can be oxidized to the aldehyde geranial. [13]

Health and safety

Geraniol is classified as D2B (Toxic materials causing other effects) using the Workplace Hazardous Materials Information System (WHMIS). [14]

History

Geraniol was first isolated in pure form in 1871 by the German chemist Oscar Jacobsen (1840–1889). [15] [16] Using distillation, Jacobsen obtained geraniol from an essential oil which was obtained from geranium grass ( Andropogon schoenanthus ) and which was produced in India. [17] The chemical structure of geraniol was determined in 1919 by the French chemist Albert Verley (1867–1959). [18]

See also

Related Research Articles

<span class="mw-page-title-main">Allyl group</span> Chemical group (–CH₂–CH=CH₂)

In organic chemistry, an allyl group is a substituent with the structural formula −CH2−HC=CH2. It consists of a methylene bridge attached to a vinyl group. The name is derived from the scientific name for garlic, Allium sativum. In 1844, Theodor Wertheim isolated an allyl derivative from garlic oil and named it "Schwefelallyl". The term allyl applies to many compounds related to H2C=CH−CH2, some of which are of practical or of everyday importance, for example, allyl chloride.

In chemistry, acetylation is an organic esterification reaction with acetic acid. It introduces an acetyl group into a chemical compound. Such compounds are termed acetate esters or simply acetates. Deacetylation is the opposite reaction, the removal of an acetyl group from a chemical compound.

<span class="mw-page-title-main">Linalool</span> Chemical compound with a floral aroma

Linalool refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent. A colorless oil, linalool is classified as an acyclic monoterpenoid. In plants, it is a metabolite, a volatile oil component, an antimicrobial agent, and an aroma compound. Linalool has uses in manufacturing of soaps, fragrances, food additives as flavors, household products, and insecticides. Esters of linalool are referred to as linalyl, e.g. linalyl pyrophosphate, an isomer of geranyl pyrophosphate.

<span class="mw-page-title-main">Appel reaction</span>

The Appel reaction is an organic reaction that converts an alcohol into an alkyl chloride using triphenylphosphine and carbon tetrachloride. The use of carbon tetrabromide or bromine as a halide source will yield alkyl bromides, whereas using carbon tetraiodide, methyl iodide or iodine gives alkyl iodides. The reaction is credited to and named after Rolf Appel, it had however been described earlier. The use of this reaction is becoming less common, due to carbon tetrachloride being restricted under the Montreal protocol.

<span class="mw-page-title-main">Benzoyl chloride</span> Organochlorine compound (C7H5ClO)

Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula C7H5ClO. It is a colourless, fuming liquid with an irritating odour, and consists of a benzene ring with an acyl chloride substituent. It is mainly useful for the production of peroxides but is generally useful in other areas such as in the preparation of dyes, perfumes, pharmaceuticals, and resins.

<span class="mw-page-title-main">Phosphorus tribromide</span> Chemical compound

Phosphorus tribromide is a colourless liquid with the formula PBr3. The liquid fumes in moist air due to hydrolysis and has a penetrating odour. It is used in the laboratory for the conversion of alcohols to alkyl bromides.

<span class="mw-page-title-main">Amidine</span> Organic compounds

Amidines are organic compounds with the functional group RC(NR)NR2, where the R groups can be the same or different. They are the imine derivatives of amides (RC(O)NR2). The simplest amidine is formamidine, HC(=NH)NH2.

<span class="mw-page-title-main">Rose oil</span> Essential oil extracted from rose petals

Rose oil is the essential oil extracted from the petals of various types of rose. Rose ottos are extracted through steam distillation, while rose absolutes are obtained through solvent extraction, the absolute being used more commonly in perfumery. The production technique originated in Greater Iran. Even with their high price and the advent of organic synthesis, rose oils are still perhaps the most widely used essential oil in perfumery.

<span class="mw-page-title-main">Pinene</span> Oily organic chemical found in plants

Pinene is a collection of unsaturated bicyclic monoterpenes. Two geometric isomers of pinene are found in nature, α-pinene and β-pinene. Both are chiral. As the name suggests, pinenes are found in pines. Specifically, pinene is the major component of the liquid extracts of conifers. Pinenes are also found in many non-coniferous plants such as camphorweed (Heterotheca) and big sagebrush.

<span class="mw-page-title-main">Myrcene</span> Chemical compound

Myrcene, or β-myrcene, is a monoterpene. A colorless oil, it occurs widely in essential oils. It is produced mainly semi-synthetically from Myrcia, from which it gets its name. It is an intermediate in the production of several fragrances. α-Myrcene is the name for the isomer 2-methyl-6-methylene-1,7-octadiene, which has not been found in nature.

<span class="mw-page-title-main">Favorskii rearrangement</span> Chemical reaction

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 rearrangement takes place in the presence of a base, sometimes hydroxide, to yield a carboxylic acid, but usually either an alkoxide base or an amine to yield an ester or an amide, respectively. α,α'-Dihaloketones eliminate HX under the reaction conditions to give α,β-unsaturated carbonyl compounds.

<span class="mw-page-title-main">Citronellol</span> Pair of enantiomers

Citronellol, or dihydrogeraniol, is a natural acyclic monoterpenoid. Both enantiomers occur in nature. (+)-Citronellol, which is found in citronella oils, including Cymbopogon nardus (50%), is the more common isomer. (−)-Citronellol is widespread, but particularly abundant in the oils of rose (18–55%) and Pelargonium geraniums.

<span class="mw-page-title-main">Nerol</span> Chemical compound

Nerol is a monoterpenoid alcohol found in many essential oils such as lemongrass and hops. It was originally isolated from neroli oil, hence its name. This colourless liquid is used in perfumery. Like geraniol, nerol has a sweet rose odor but it is considered to be fresher. Esters and related derivatives of nerol are referred to as neryl, e.g., neryl acetate.

<span class="mw-page-title-main">Isoborneol</span> Chemical compound

Isoborneol is a bicyclic organic compound and a terpene derivative. The hydroxyl group in this compound is placed in an exo position. The endo diastereomer is called borneol. Being chiral, isoborneol exists as enantiomers.

<span class="mw-page-title-main">Geranyl pyrophosphate</span> Chemical compound

Geranyl pyrophosphate (GPP), also known as geranyl diphosphate (GDP), is the pyrophosphate ester of the terpenoid geraniol. Its salts are colorless. It is a precursor to many natural products.

<i>Pelargonium graveolens</i> Species of plant

Pelargonium graveolens is a Pelargonium species native to the Cape Provinces and the Northern Provinces of South Africa, Zimbabwe and Mozambique.

<span class="mw-page-title-main">Geranyl acetate</span> Chemical compound

Geranyl acetate is a terpenoid. It is a colorless liquid with a pleasant floral or fruity rose aroma. It is a colorless liquid but commercial samples can appear yellowish. Geranyl acetate is insoluble in water but soluble in organic solvents. Several hundred tons are produced annually.

Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen functionality or missing a methyl group, are called monoterpenoids. Monoterpenes and monoterpenoids are diverse. They have relevance to the pharmaceutical, cosmetic, agricultural, and food industries.

<span class="mw-page-title-main">2-Chloropropionic acid</span> Chemical compound

2-Chloropropionic acid (2-chloropropanoic acid) is the chemical compound with the formula CH3CHClCO2H. This colorless liquid is the simplest chiral chlorocarboxylic acid, and it is noteworthy for being readily available as a single enantiomer. The conjugate base of 2-chloropropionic acid (CH3CHClCO2), as well as its salts and esters, are known as 2-chloropropionates or 2-chloropropanoates.

References

  1. "Geraniol". The Merck Index (12th ed.).
  2. 1 2 3 Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  3. "Geraniol_msds".
  4. "GERANIOL - Cameo Chemicals - NOAA" . Retrieved 26 June 2021.
  5. Danka, R. G.; Williams, J. L.; Rinderer, T. E. (1990). "A bait station for survey and detection of honey bees" (PDF). Apidologie. 21 (4): 287–292. doi: 10.1051/apido:19900403 .
  6. Müller, Günter C.; Junnila, Amy; Kravchenko, Vasiliy D.; Revay, Edita E.; Butler, Jerry; Orlova, Olga B.; Weiss, Robert W.; Schlein, Yosef (March 2008). "Ability of essential oil candles to repel biting insects in high and low biting pressure environments". Journal of the American Mosquito Control Association. 24 (1): 154–160. doi:10.2987/8756-971X(2008)24[154:AOEOCT]2.0.CO;2. ISSN   8756-971X. PMID   18437832. S2CID   41927381.
  7. Holcombe, Luke (9 January 2018) "Wine faults", p. 11.
  8. Eggersdorfer, M. "Terpenes". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a26_205. ISBN   978-3527306732.
  9. Fellermeier M, Zenk MH (May 1998). "Prenylation of olivetolate by a hemp transferase yields cannabigerolic acid, the precursor of tetrahydrocannabinol". FEBS Letters. 427 (2): 283–85. doi: 10.1016/S0014-5793(98)00450-5 . PMID   9607329.
  10. Stork, Gilbert; Grieco, Paul A.; Gregson, Michael (1974). "Allylic Chlorides from Allylic Alcohols: Geranyl Chloride". Organic Syntheses . 54: 68. doi:10.15227/orgsyn.054.0068.
  11. Jose G. Calzada and John Hooz (1974). "Geranyl chloride". Organic Syntheses . 54: 63. doi:10.15227/orgsyn.054.0063.
  12. Takaya, Hidemasa; Ohta, Tetsuo; Inoue, Shin-ichi; Tokunaga, Makoto; Kitamura, Masato; Noyori, Ryoji (1995). "Asymmetric Hydrogenation of Allylic Alcohols Using BINAP–Ruthenium Complexes: (S)-(−)-citronellol". Organic Syntheses . 72: 74. doi:10.15227/orgsyn.072.0074.; Collective Volume, vol. 9, p. 169
  13. Piancatelli, Giovanni; Leonelli, Francesca (2006). "Oxidation of Nerol to Neral With Iodosobenzene and TEMPO". Organic Syntheses . 83: 18. doi:10.15227/orgsyn.083.0018.
  14. "MSDS – Geraniol". Sigma-Aldrich. Retrieved Feb 15, 2022.
  15. Jacobsen, Oscar (1871). "Untersuchung der indischen Geraniumöls" [InvestIgation of Indian oil from geranium [grass]]. Annalen der Chemie und Pharmacie (in German). 157: 232–239. Jacobsen named geraniol on p. 234: "Danach ist dieser Körper, das Geraniol, isomer mit dem Borneol … " (Accordingly this body [i.e., substance], geraniol, is isomeric with borneol … )
  16. Semmler, F.W. (1906). Die ätherischen Öle [The Volatile Oils] (in German). Vol. 1. Leipzig, Germany: Von Veit & Co. p. 292. From p. 292: "Von dem Geraniol ist zu erwähnen, daß … erst Jacobsen (A. 157, 232) brachte im Jahre 1870 über den Alkohol, den er Geraniol nannte, nähere Angaben, er stellte die Formel C10H18O auf, ohne weitere Konstitionsangaben zu machen." (It should be mentioned about geraniol that … Jacobsen (A. 157, 232) first gathered in 1870 more detailed data about the alcohol, which he named geraniol ; he established its [empirical] formula C10H18O, without providing further data about its chemical structure.) See also: § 49. Geraniol C10H18O, pp. 439-493. On p. 439, two hypothetical structures of geraniol are proposed.
  17. (Semmler, 1906), p. 491.
  18. Verley, Albert (1919). "Sur la constitution du géraniol, du linalool et du nérol" [On the chemical structure of geraniol, linalool, and nerol]. Bulletin de la Société Chimique de France. 4th series (in French). 25: 68–80. The chemical structure of geraniol appears on p. 70.