Terpineol

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alpha-Terpineol
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 YesY
ChemSpider 13850142 YesY
UNII 21334LVV8W YesY
ChEBI CHEBI:22469 YesY
ChEMBL CHEMBL507795 N
Jmol-3D images Image 1
Properties
Molecular formula C10H18O
Molar mass 154.25 g/mol
Density 0.9338 g/cm3
Melting point 18 °C
Boiling point 219 °C
81-82 °C at 4.5 mmHg
Hazards
MSDS External MSDS
NFPA 704
1
2
0
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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 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.

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 starting from d-limonene was demonstrated:[3]

Terpineol synthesisfrom limonene

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

  1. ↑ Merck Index, 11th Edition, 9103
  2. ↑ 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). 
  3. ↑ 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. doi:10.1021/op068012d. 

External links

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