Terpineol

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 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.


 * [[Image:Terpineols.png|400px|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.

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 :


 * [[Image:Terpineolsynthesisfromlimonene.png|400px|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.