Terpineol

alpha-terpineol
Skeletal formula	Ball-and-stick model
Names
	IUPAC names p-Menth-1-en-8-ol; 2-(4-Methylcyclohex-3-en-1-yl)propan-2-ol
	Other names 2-(4-Methyl-1-cyclohex-3-enyl)propan-2-ol; alpha-terpineol; α-terpineol; α,α,4-Trimethylcyclohex-3-ene-1-methanol; Terpene alcohol
Identifiers
CAS Number	α:98-55-5; β:138-87-4; γ:586-81-2; 4-:562-74-3;
3D model (JSmol)	α:Interactive image;
Beilstein Reference	2325137
ChEBI	α:CHEBI:22469; β:CHEBI:132899; γ:CHEBI:81151; 4-:CHEBI:78884;
ChEMBL	α:ChEMBL507795; 4-:ChEMBL507795;
ChemSpider	α:13850142; β:8418; γ:10983; 4-:10756;
EC Number	α: 202-680-6; β:205-342-6; γ:209-584-3; 4-: 209-235-5;
KEGG	β:C17517; 4-:C17073;
PubChemCID	α:17100; β:8748; γ:11467; 4-:11230;
UNII	α:21334LVV8W; γ:5PH9U7XEWS;
CompTox Dashboard(EPA)	4-:DTXSID4044824;
	InChI InChI=1S/C10H18O/c1-8-4-6-9(7-5-8)10(2,3)11/h4,9,11H,5-7H2,1-3H3 Key: WUOACPNHFRMFPN-UHFFFAOYSA-N; α: InChI=1/C10H18O/c1-8-4-6-9(7-5-8)10(2,3)11/h4,9,11H,5-7H2,1-3H3 Key: WUOACPNHFRMFPN-UHFFFAOYAL;
	SMILES α: C\C1=C\CC(CC1)C(O)(C)C;
Properties
Chemical formula	C10H18O
Molar mass	154.253g·mol−1
Appearance	Colorless liquid
Density	0.93g/cm3
Melting point	−35.9 to −28.2 °C (−32.6 to −18.8 °F; 237.2 to 245.0 K)(mixture of isomers)
Boiling point	214–217 °C (417–423 °F; 487–490 K)(mixture of isomers)
Solubility in water	2.42g/L
Magnetic susceptibility(χ)	−111.9·10−6cm3/mol
Hazards
NFPA 704(fire diamond)	2 1 0
Flash point	88 °C (190 °F; 361 K)
Safety data sheet(SDS)	External MSDS
	Except where otherwise noted, data are given for materials in theirstandard state(at 25 °C [77 °F], 100 kPa). verify(what is?) Infobox references

Terpineolis any of fourisomeric monoterpenoids.Terpenoids are terpene that are modified by the addition of afunctional group,in this case, analcohol.Terpineols have been isolated from a variety of sources such ascardamom,cajuput oil,pine oil,andpetitgrainoil.^[2]Fourisomersexist: α-, β-, γ-terpineol, andterpinen-4-ol.β- and γ-terpineol differ only by the location of thedouble bond.Terpineol is usually a mixture of these isomers with α-terpineol as the major constituent.

Terpineols: alpha-, beta-, gamma-, and the 4-terpineol isomer

Terpineol has a pleasant odor similar to lilac and is a common ingredient in perfumes, cosmetics, and flavors. α-Terpineol is one of the two most abundantaromaconstituents oflapsang souchongtea; the α-terpineol originates in the pine smoke used to dry the tea.^[3](+)-α-terpineol is a chemical constituent ofskullcap.

Synthesis and biosynthesis

Although it is naturally occurring, terpineol is commonly manufactured fromalpha-pinene,which is hydrated in the presence of sulfuric acid.^[4]

An alternative route starts fromlimonene:^[5]

Terpineol synthesis from limonene

Limonene reacts withtrifluoroacetic acidin aMarkovnikov additionto a trifluoroacetate intermediate, which is easily hydrolyzed withsodium hydroxideto α-terpineol with 7% selectivity. Side-products are β-terpineol in a mixture of thecisisomer, thetransisomer,and 4-terpineol.

The biosynthesis of α-terpineol proceeds from geranyl pyrophosphate, which releases pyrophosphate to give theterpinyl cation.This carbocation is the precursor to many terpenes and terpenoids. Its hydrolysis gives terpineol.

Biosynthetic conversion ofgeranyl pyrophosphateto the terpenesα-pineneandβ-pinene(right) and to α-terpineol (bottom left).^[6]

References

^^a ^b ^c ^d ^e ^fRecordin theGESTIS Substance Databaseof theInstitute for Occupational Safety and Health
^Merck Index,11th Edition,9103
^Shan-Shan Yao; Wen-Fei Guo; Yi Lu; Yuan-Xun Jiang (2005)."Flavor Characteristics of Lapsang Souchong and Smoked Lapsang Souchong, a Special Chinese Black Tea with Pine Smoking Process".Journal of Agricultural and Food Chemistry.53(22): 8688–93.doi:10.1021/jf058059i.PMID 16248572.
^Gscheidmeier, Manfred; Fleig, Helmut (June 15, 2000). "Turpentines, 16. Pine Oil".Ullmann's Encyclopedia of Industrial Chemistry.Weinheim: Wiley-VCH.doi:10.1002/14356007.a27_267.ISBN 978-3527306732.
^Yuasa, Yoshifumi; Yuasa, Yoko (2006). "A Practical Synthesis ofd-α-Terpineol via Markovnikov Addition ofd-limonene Using Trifluoroacetic Acid ".Organic Process Research & Development.10(6): 1231–1232.doi:10.1021/op068012d.
^Davis, Edward M.; Croteau, Rodney (2000). "Cyclization enzymes in the biosynthesis of monoterpenes, sesquiterpenes, and diterpenes".Biosynthesis.Vol. 209. pp. 53–95.doi:10.1007/3-540-48146-X_2.ISBN 978-3-540-66573-1.{{cite book}}:|journal=ignored (help)

External links

MSDS for alpha-terpineol
Media related toTerpineolsat Wikimedia Commons

[GESTIS-1] Recordin theGESTIS Substance Databaseof theInstitute for Occupational Safety and Health

[2] Merck Index,11th Edition,9103

[3] Shan-Shan Yao; Wen-Fei Guo; Yi Lu; Yuan-Xun Jiang (2005)."Flavor Characteristics of Lapsang Souchong and Smoked Lapsang Souchong, a Special Chinese Black Tea with Pine Smoking Process".Journal of Agricultural and Food Chemistry.53(22): 8688–93.doi:10.1021/jf058059i.PMID 16248572.

[Ull-4] Gscheidmeier, Manfred; Fleig, Helmut (June 15, 2000). "Turpentines, 16. Pine Oil".Ullmann's Encyclopedia of Industrial Chemistry.Weinheim: Wiley-VCH.doi:10.1002/14356007.a27_267.ISBN 978-3527306732.

[5] Yuasa, Yoshifumi; Yuasa, Yoko (2006). "A Practical Synthesis ofd-α-Terpineol via Markovnikov Addition ofd-limonene Using Trifluoroacetic Acid ".Organic Process Research & Development.10(6): 1231–1232.doi:10.1021/op068012d.

[Crot-6] Davis, Edward M.; Croteau, Rodney (2000). "Cyclization enzymes in the biosynthesis of monoterpenes, sesquiterpenes, and diterpenes".Biosynthesis.Vol. 209. pp. 53–95.doi:10.1007/3-540-48146-X_2.ISBN 978-3-540-66573-1.{{cite book}}:|journal=ignored (help)

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