What molecule am I?
α-Terpineol is a terpene alcohol that is found in natural oils such as pine oil and petitgrain (the oil from the bitter orange tree). It is the most common of four structural isomers; the others are β-, γ-, and 4-terpineol. It should not be confused with terpinol, the hydrate of terpin, a terpene diol.
α-Terpineol is a racemic mixture of (R)-(+)- and (S)-(–)-enantiomers. Both are found in nature; but the article of commerce, which is usually synthesized from α-pinene, is the racemate. In 1903, German chemists H. Waldbaum and O. Hüthig isolated the (+)-stereoisomer from petitgrain. Four years later, J. E. Teeple of New York City separated its enantiomer from long-leaf pine oil.
The lilac-like aroma of α-terpineol makes it a desirable ingredient for perfumes and cosmetics. This time of year, people burn α-terpineol-scented candles for their piney scent. Whatever your favorite aroma during the holidays, enjoy the season!
MOTW update
Fentanyl was the Molecule of the Week for December 11, 2017. The potent painkiller is one of the main culprits of the current opioid abuse epidemic in the United States. On December 13, as part of the effort to keep illicit fenanyl out of the country, US Customs Border Protection seized ≈35 kg of the drug at the San Ysidro, CA, port of entry. This quantity surpassed the previous record confiscation of ≈30 kg this past June.
α-Terpineol fast facts
| CAS Reg. No. | 98-55-5 |
| Molar mass | 154.25 g/mol |
| Formula | C10H18O |
| Appearance | Colorless liquid |
| Boiling point | ≈217–219 ºC |
| Water solubility | 2.4 g/L |
Learn more about this molecule from CAS, the most authoritative and comprehensive source for chemical information.
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