Citronellol

Preparation

Several million kilograms of citronellol are produced annually. It is mainly obtained by partial hydrogenation of geraniol or nerol over copper chromite catalyst. Hydrogenation of both C=C bonds using a nickel catalyst gives tetrahydrogeraniol, yet another commercial fragrance.

Homogeneous catalysts have been investigated for the production of enantiomers.

Uses

Citronellol is used in perfumes and as a fragrance in cleaning products. In many applications, one of the enantiomers is preferred. It is a component of citronella oil, an insect repellant.

Citronellol is used as a raw material for the production of rose oxide. It is also a precursor to many commercial and potential fragrances such as citronellol acetate, citronellyl oxyacetaldehyde, citronellyl methyl acetal, and ethyl citronellyl oxalate.

Health and safety

The United States FDA considers citronellol as generally recognized as safe (GRAS) for food use. Citronellol is subject to restrictions on its use in perfumery, as some people may become sensitised to it, but the degree to which citronellol can cause an allergic reaction in humans is disputed.

In terms of dermal safety, citronellol has been evaluated as an insect repellent.

References

References

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5. (1995). "Catalytic Synthesis of (''R'')- and (''S'')-citronellol by homogeneous hydrogenation over amidophosphinephosphinite and diaminodiphosphine rhodium complexes". Tetrahedron: Asymmetry.
6. (2010). ""Dark" Singlet Oxygenation of β-Citronellol: A Key Step in the Manufacture of Rose Oxide". Organic Process Research & Development.
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12. (2013). "Reduction of mosquito biting-pressure: Spatial repellents or mosquito traps? A field comparison of seven commercially available products in Israel". Acta Tropica.
13. (2011). "Investigation of inclusion complexes of citronella oil, citronellal and citronellol with β-cyclodextrin for mosquito repellent". Journal of Inclusion Phenomena and Macrocyclic Chemistry.