Terpineol

*alpha*-Terpineol
Names
	IUPAC name 2-(4-Methyl- 1-cyclohex- 3-enyl) propan- 2-ol
	Other names alpha-Terpineol ; α-Terpineol ; p-Menth- 1-en-8-ol ; α,α,4- Trimethylcyclohex- 3-ene- 1-methanol ; Terpene alcohol
Identifiers
CAS Number	98-55-5 ;
3D model (JSmol)	Interactive image;
	SMILES CC1=CCC(C(C)(O)C)CC1;
Properties
Chemical formula	C10H18O
Molar mass	154.25 g/mol
Density	0.9338 g/cm3
Melting point	39 °C
Boiling point	219 °C; 81-82 °C at 4.5 mmHg
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Terpineol is a naturally occurring monoterpene alcohol that has been isolated from a variety of sources such as cajuput oil, pine oil, and petitgrain oil^[1]. There are three isomers, alpha-, beta-, and gamma-terpineol, the last two differing only by the location of the double bond. Terpineol is usually a mixture of these isomers with alpha-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 abundant aroma constituents of lapsang souchong tea; the α-terpineol originates in the pine smoke used to dry the tea.^[2]

Although it is naturally occurring, terpineol is commonly manufactured from the more readily available alpha-pinene.

In one study an alternative route was demonstrated starting from d-limonene^[3]:

Limonene is reacted with trifluoroacetic acid in a Markovnikov addition to a trifluoro acetate intermediate which is easily hydrolyzed with sodium hydroxide to α-terpineol with 76% selectivity. Side products are the β-terpineol in a mixture of cis-isomer and trans isomer and 4-terpineol.

References

^ Merck Index, 11th Edition, 9103.
^ Shan-Shan Yao； Wen-Fei Guo； YI Lu； Yuan-Xun Jiang, "Flavor Characteristics of Lapsang Souchong and Smoked Lapsang Souchong,a Special Chinese Black Tea with Pine Smoking Process", Journal of Agricultural and Food Chemistry, Vol. 53, No.22, (2005)
^ A Practical Synthesis of d--Terpineol via Markovnikov Addition of d-Limonene Using Trifluoroacetic Acid Yoshifumi Yuasa and Yoko Yuasa Org. Process Res. Dev.; 2006; 10(6) pp 1231 - 1232; (Article) doi:10.1021/op068012d

External links

[1] Merck Index, 11th Edition, 9103.

[2] Shan-Shan Yao； Wen-Fei Guo； YI Lu； Yuan-Xun Jiang, "Flavor Characteristics of Lapsang Souchong and Smoked Lapsang Souchong,a Special Chinese Black Tea with Pine Smoking Process", Journal of Agricultural and Food Chemistry, Vol. 53, No.22, (2005)

[3] A Practical Synthesis of d--Terpineol via Markovnikov Addition of d-Limonene Using Trifluoroacetic Acid Yoshifumi Yuasa and Yoko Yuasa Org. Process Res. Dev.; 2006; 10(6) pp 1231 - 1232; (Article) doi:10.1021/op068012d

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