Borneol


Borneol is a bicyclic organic compound and a terpene derivative. The hydroxyl group in this compound is placed in an endo position. There are two different enantiomers of borneol. Both -borneol and -borneol are found in nature.

Reactions

Borneol is easily oxidized to the ketone. One historical name for borneol is Borneo camphor which explains the name. Borneol can be synthesized by reduction of camphor by the Meerwein–Ponndorf–Verley reduction. Reduction of camphor with sodium borohydride gives instead the isomer isoborneol as the kinetically controlled reaction product.

Natural occurrences

Borneol can be found in several species of Heterotheca, Artemisia, Callicarpa, Dipterocarpaceae, Blumea balsamifera and Kaempferia galanga.
It is one of the chemical compounds found in castoreum. This compound is gathered from the beaver's plant food.

Uses

Whereas d-borneol was the enantiomer that used to be the most readily available commercially, the more commercially available enantiomer now is l-borneol, which also occurs in nature.
Borneol is used in traditional Chinese medicine. An early description is found in the Bencao Gangmu.
Borneol is a component of many essential oils and it is a natural insect repellent.

Use in organic chemistry

Derivatives of isoborneol are used as chiral ligands in asymmetric synthesis:
Borneol is an eye, skin, and respiratory irritant; it is harmful if swallowed.

Derivatives

The bornyl group is a univalent radical C10H17 derived from borneol by removal of hydroxyl and is also known as 2-bornyl. Isobornyl is the univalent radical C10H17 that is derived from isoborneol.
Bornyl acetate is the acetate ester of borneol.