Terpineol

Names IUPAC namesOther names Identifiers 2325137 ChEBIChEMBLChemSpiderEC NumberKEGGUNIIProperties C₁₀H₁₈OMolar mass154.253 g·mol Appearance Colorless liquid OdorPleasant, lilac-like Density0.93g/cm Melting point−35.9 to −28.2 °C (−32.6 to −18.8 °F; 237.2 to 245.0 K) (mixture of isomers) Boiling point214–217 °C (417–423 °F; 487–490 K) (mixture of isomers) 2.42g/L −111.9×10 cm/molHazards NFPA 704 (fire diamond) Flash point88 °C (190 °F; 361 K) Safety data sheet (SDS) External MSDS

Terpineol is any of four isomericmonoterpenoids. Terpenoids are terpene that are modified by the addition of a functional group, in this case, an alcohol. Terpineols have been isolated from a variety of sources such as cardamom, cajuput oil, pine oil, and petitgrain oil. Four isomers exist: α-terpineol, β-terpineol, γ-terpineol, and terpinen-4-ol. β-Terpineol and γ-terpineol differ only by the location of the double bond. Terpineol is usually a mixture of these isomers with α-terpineol as the major constituent.

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 skullcap.

α-Terpineol has an aroma described as "pine, terpenic, lilac, citrus, woody, floral, resinous, cooling, lemon, lime". Whilst both enantiomers of α-terpineol exhibit a floral lilac aroma, the laevo form (−)-α-terpineol, is reportedly more terpenic. The aroma of β-terpineol is described as "pungent, earthy, woody".. The aroma of γ-terpineol is "pine, floral, lilac". 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".