Terpineol

alpha-Terpineol

Ball-and-stick model
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 Y
ChEBI	CHEBI:22469 Y
ChEMBL	ChEMBL507795 N
ChemSpider	13850142 Y
Jmol 3D model	Interactive image
UNII	21334LVV8W Y
InChI InChI=1S/C10H18O/c1-8-4-6-9(7-5-8)10(2,3)11/h4,9,11H,5-7H2,1-3H3 Y Key: WUOACPNHFRMFPN-UHFFFAOYSA-N Y 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 C\C1=C\CC(CC1)C(O)(C)C
Properties
Chemical formula	C10H18O
Molar mass	154.25 g·mol−1
Appearance	Colorless liquid
Density	0.93 g/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	2.42 g/L
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
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. There are four isomers, alpha-, beta-, gamma-terpineol, and terpinen-4-ol. beta- and gamma-terpineol differ only by the location of the double bond. Terpineol is usually a mixture of these isomers with alpha-terpineol as the major constituent.

File:Terpineols.png

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. (+)-α-Terpineol is a chemical constituent of scullcap.

Synthesis

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

In one study, an alternative route starting from d-limonene was demonstrated:

File:Terpineolsynthesisfromlimonene.png

Terpineol synthesisfrom limonene

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

External links

• MSDS for alpha-terpineol
• Media related to at Wikimedia Commons