Fenchol

Fenchole ( 1,3,3- trimethyl-2 -nor- bornanole ) are bicyclic monoterpene alcohols with molecular formula C10H18O and the molar mass of 154.25 g · mol -1. Of the isomer with borneol natural product, there are four stereoisomers, namely the α - Fenchole [( ) - and ( -)- α - fenchol ] and β - Fenchole [( ) - and ( -)- β - fenchol ], wherein which the hydroxy group is above the levels of the six-membered ring. Are sometimes found in rosemary, hops, nutmeg oil and pine oil, and fruits before as the lime, grapefruit and peel of the orange.

Properties

Natural, extracted from plants fenchol is always a mixture of the four isomers (CAS 1632-73-1 ) with a total of camphor - like odor, the composition of which depends on the plant species. Therefore, it is also for the mixture no definite melting point ( from 35 to 40 ° C), or boiling (~ 200 ° C). The individual isomers each have their own smell, ranging from lime -like over camphor- up to woody, earthy. The taste is bitter and lime -like. In water, the Fenchole are almost insoluble in ethanol, however, readily soluble. The ( )- α - isomer is irritating to eyes, skin and mucous membranes.

Isomers

Representation, reactions, and use

Fenchole can be prepared by reduction with sodium in ethanol by fenchone. By dehydration of Fencholen occur rarely in essential oils occurring unsaturated Fenchene.

(-)- Α - fenchol is used as component of perfume. Also in bergamot oil contains small amounts Fenchole.

Natural fenchol (CAS 1632-73-1 ) has in the United States classification as FEMA GRAS (Generally Reported As Safe, GRAS FEMA # 2480 ), and can thus be used as a food additive. 2003 in the USA 316.67 pounds ( = 143.6 kg ) Fenchole used as odorants; the allowable daily dose was set at 0,533 mg.