# Terpineol

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Terpineol
> Markdown URL: https://mediated.wiki/source/Terpineol.md
> Source: https://en.wikipedia.org/wiki/Terpineol
> Source revision: 1350382036
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{chembox
| Verifiedfields = changed
| Watchedfields  = changed
| verifiedrevid  = 470602595
| Name           = alpha-terpineol
| ImageFileL1    = Terpineol alpha.svg
| ImageNameL1    = Skeletal formula
| ImageFileR1    = Alpha-terpineol-3D-balls.png
| ImageNameR1    = Ball-and-stick model
| ImageName      = alpha-Terpineol
| IUPACNames     = ''p''-Menth-1-en-8-ol<br>2-(4-Methylcyclohex-3-en-1-yl)propan-2-ol
| OtherNames     = {{Unbulleted list|2-(4-Methyl-1-cyclohex-3-enyl)propan-2-ol|alpha-Terpineol|α-Terpineol|α,α,4-Trimethylcyclohex-3-ene-1-methanol|Terpene alcohol|Terpineol AP}}
| Section1       = {{Chembox Identifiers
| index_label = α
| index1_label = β
| index2_label = γ
| index3_label = 4-
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 98-55-5
| CASNo1 = 138-87-4
| CASNo2 = 586-81-2
| CASNo3 = 562-74-3
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 22469
| ChEBI1 = 132899
| ChEBI2 = 81151
| ChEBI3 = 78884
| Beilstein = 2325137
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 13850142
| ChemSpiderID1 = 8418
| ChemSpiderID2 = 10983
| ChemSpiderID3 = 10756
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 507795
| ChEMBL3 = 507795
| DTXSID3 = DTXSID4044824
| EC_number = 202-680-6
| EC_number1 =205-342-6
| EC_number2 = 209-584-3
| EC_number3 = 209-235-5
| KEGG1 = C17517
| KEGG3 = C17073
| PubChem = 17100
| PubChem1 = 8748
| PubChem2 = 11467
| PubChem3 = 11230
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 21334LVV8W
| UNII2 = 5PH9U7XEWS
| InChI = 1/C10H18O/c1-8-4-6-9(7-5-8)10(2,3)11/h4,9,11H,5-7H2,1-3H3
| InChIKey = WUOACPNHFRMFPN-UHFFFAOYAL
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C10H18O/c1-8-4-6-9(7-5-8)10(2,3)11/h4,9,11H,5-7H2,1-3H3
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = WUOACPNHFRMFPN-UHFFFAOYSA-N
| SMILES = C\C1=C\CC(CC1)C(O)(C)C
}}
| Section2       = {{Chembox Properties
| C=10 | H=18 | O=1
| Density = 0.93{{nbsp}}g/cm<sup>3</sup><ref name=GESTIS/>
| MeltingPtC = -35.9 to -28.2
| MeltingPt_notes = (mixture of isomers)
| MeltingPt_ref = <ref name=GESTIS>{{GESTIS|ZVG=122876}}</ref>
| BoilingPtC = 214–217
| BoilingPt_notes = (mixture of isomers)
| BoilingPt_ref = <ref name=GESTIS/>
| Solubility = 2.42{{nbsp}}g/L<ref name=GESTIS/>
| Appearance = Colorless liquid<ref name=GESTIS/>
|Odor = Pleasant, lilac-like
| MagSus = {{val|-111.9e-6|u=cm<sup>3</sup>/mol}}
 }}
| Section3       = {{Chembox Hazards
| ExternalSDS = [http://hazard.com/msds/mf/baker/baker/files/t0364.htm External MSDS]
| NFPA-H = 2
| NFPA-F = 1
| NFPA-R = 0
| NFPA-S = 
| HPhrases = 
| PPhrases = 
| GHS_ref  = 
| FlashPtC = 88
| FlashPt_ref = <ref name=GESTIS/>
 }}
}}

'''Terpineol''' is any of four [isomer](/source/isomer)ic [monoterpenoid](/source/monoterpene)s.  Terpenoids are terpene that are modified by the addition of a [functional group](/source/functional_group), in this case, an [alcohol](/source/Alcohol_(chemistry)).  Terpineols have been isolated from a variety of sources such as [cardamom](/source/cardamom), [cajuput oil](/source/cajuput_oil), [pine oil](/source/pine_oil), and [petitgrain](/source/petitgrain) oil.<ref>{{Merck11th|page=9103}}</ref> Four [isomer](/source/isomer)s exist: α-terpineol, β-terpineol, γ-terpineol, and [terpinen-4-ol](/source/terpinen-4-ol). β-Terpineol and γ-terpineol differ only by the location of the [double bond](/source/double_bond). Terpineol is usually a mixture of these isomers with α-terpineol as the major constituent.

:left|thumb|350x350px|Terpineols: alpha-, beta-, gamma-, and the 4-terpineol isomer{{clear left}}

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 abundant [aroma](/source/aroma) constituents of [lapsang souchong](/source/lapsang_souchong) tea; the α-terpineol originates in the pine smoke used to dry the tea.<ref>{{cite journal|first1=Shan-Shan |last1=Yao |first2=Wen-Fei |last2=Guo |first3=Yi |last3=Lu |first4=Yuan-Xun |last4=Jiang |year=2005 |title=Flavor Characteristics of Lapsang Souchong and Smoked Lapsang Souchong, a Special Chinese Black Tea with Pine Smoking Process |journal=Journal of Agricultural and Food Chemistry |volume=53 |issue=22 |url=http://d.wanfangdata.com.cn/NSTLQK_NSTL_QK10615205.aspx | doi = 10.1021/jf058059i |pmid=16248572 |pages=8688–93|bibcode=2005JAFC...53.8688Y |url-access=subscription }}</ref> (+)-α-Terpineol is a chemical constituent of [skullcap](/source/Scutellaria_barbata).

α-Terpineol has an aroma described as "pine, terpenic, lilac, citrus, woody, floral, resinous, cooling, lemon, lime".<ref>{{cite web |title=alpha-terpineol|url=https://scentsandflavors.com/database/9dbb5015-fa2b-41f8-b35a-ca01a4d81ef8|website=Scents and Flavors |publisher=Scents and Flavors |access-date=5 April 2026}}</ref> Whilst both [enantiomer](/source/enantiomer)s of α-terpineol exhibit a floral lilac aroma,<ref>{{cite web |title=(+)-alpha-terpineol|url=https://scentsandflavors.com/database/9dbb56dc-3c69-4941-9c60-5b2e9104c16c|website=Scents and Flavors |publisher=Scents and Flavors |access-date=5 April 2026}}</ref><ref>{{cite web |title=(−)-alpha-terpineol|url=https://scentsandflavors.com/database/9dbb5385-fca8-44da-a482-7b657f14d108|website=Scents and Flavors |publisher=Scents and Flavors |access-date=5 April 2026}}</ref> the laevo form (−)-α-terpineol, is reportedly more terpenic. The aroma of β-terpineol is described as "pungent, earthy, woody".<ref>{{cite web |title=beta-terpineol|url=https://scentsandflavors.com/database/9dbb511e-74cd-4aed-bc09-6c723bb99a01|website=Scents and Flavors |publisher=Scents and Flavors |access-date=5 April 2026}}</ref>. The aroma of γ-terpineol is "pine, floral, lilac".<ref>{{cite web |title=gamma-terpineol|url=https://scentsandflavors.com/database/9dbb51e7-21f2-46d9-ad96-5d1381b4e383|website=Scents and Flavors |publisher=Scents and Flavors |access-date=5 April 2026}}</ref> The aroma of 4-terpinenol (also known as terpinen-4-ol or 4-carvomenthenol), is described as "peppery, woody, earthy, musty, sweet, mentholic, citrus, terpenic, spicy".<ref>{{cite web |title=4-carvomenthenol|url=https://scentsandflavors.com/database/9dbb50aa-eb18-4874-bde4-3a99de690275|website=Scents and Flavors |publisher=Scents and Flavors |access-date= 5 April 2026}}</ref>

==Synthesis and biosynthesis==
Although it is naturally occurring, terpineol is commonly manufactured from [alpha-pinene](/source/alpha-pinene), which is hydrated in the presence of sulfuric acid.<ref name=Ull>{{Ullmann|title= Turpentines, 16. Pine Oil |first1= Manfred |last1= Gscheidmeier |first2= Helmut |last2= Fleig |date= June 15, 2000 |doi=10.1002/14356007.a27_267|isbn = 978-3527306732}}</ref>

An alternative route starts from [limonene](/source/limonene):<ref>{{cite journal | doi = 10.1021/op068012d | title = A Practical Synthesis of ''d''-α-Terpineol via Markovnikov Addition of ''d''-Limonene Using Trifluoroacetic Acid | year = 2006 | last1 = Yuasa | first1 = Yoshifumi | last2 = Yuasa | first2 = Yoko | journal = Organic Process Research & Development | volume = 10 | issue = 6 | pages = 1231–1232}}</ref>

:thumb|left|400px|Terpineol synthesis from limonene{{clear left}}

Limonene reacts with [trifluoroacetic acid](/source/trifluoroacetic_acid) in a [Markovnikov addition](/source/Markovnikov's_rule) to a trifluoroacetate intermediate, which is easily hydrolyzed with [sodium hydroxide](/source/sodium_hydroxide) to α-terpineol with 7% selectivity. Side-products are β-terpineol in a mixture of the [''cis'' isomer, the ''trans'' isomer](/source/Cis%E2%80%93trans_isomerism), and 4-terpineol.

The biosynthesis of α-terpineol proceeds from geranyl pyrophosphate, which releases pyrophosphate to give the '''terpinyl cation'''.  This carbocation is the precursor to many terpenes and terpenoids.  Its hydrolysis gives terpineol.
:[[File:TerpeneVterpenoid.svg|thumb|460px|left|Biosynthetic conversion of [geranyl pyrophosphate](/source/geranyl_pyrophosphate) to the terpenes [α-pinene](/source/Alpha-pinene) and [β-pinene](/source/Beta-pinene) (right) and to α-terpineol (bottom left).<ref name=Crot>{{cite book|chapter=Cyclization enzymes in the biosynthesis of monoterpenes, sesquiterpenes, and diterpenes|last1=Davis |first1=Edward M. |last2=Croteau |first2=Rodney |title=Biosynthesis|journal=Topics in Current Chemistry|year=2000|volume=209|pages=53–95|doi=10.1007/3-540-48146-X_2|isbn=978-3-540-66573-1}}</ref>]]
{{clear left}}

==References==
{{reflist}}

==External links==
* [http://hazard.com/msds/mf/baker/baker/files/t0364.htm MSDS for alpha-terpineol]
* {{commons category-inline}}

{{Authority control}}

Category:Flavors
Category:Monoterpenes
Category:Alkenols
Category:Cyclohexenes

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Adapted from the Wikipedia article [Terpineol](https://en.wikipedia.org/wiki/Terpineol) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Terpineol?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.