The chemistry of essential oils and artificial perfumes / by Ernest J. Parry.

  • Parry, Ernest J. (Ernest John)
Date:
1908
Catalogue details

Licence: In copyright

Credit: The chemistry of essential oils and artificial perfumes / by Ernest J. Parry. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    54/594 (page 42)
    ESSENTIAL OILS. 172°. When mixtures of the semicarbazones of /3-thujone or of a-thujone, or of both, are present, they give rise to com- plications which become even more pronounced owing to the fact that mixed crystals of uniform appearance are formed which can only be split up by very frequent recrystallisation. The ketone liberated from the semicarbazone by means of phthalic anhydride has the specific rotatory power [a] + 76-16°. Its oxime melts at 54° to 55°, and is dextro-rotatory. /3-thujone can also be converted into the isomeric a-thujone by boiling with alcoholic potash. The various compounds of this ketone are closely analogous to those of the isomers already described. Thujone is easily converted into the isomeric ketones, isothujone and carvotanacetone. The former results by heating thujone with 40 per cent, sulphuric acid, whilst the latter is formed by heating thujone in a closed tube to 280°. The more interesting of these isomers is isothujone, for on reduction with sodium and alcohol, an alcohol C10H19OH results, which is isomeric with menthol, and which is sufficiently similar to this body in its properties to be termed thujamenthol. Thujamenthol on oxidation yields the ketone thujamenthone, which is isomeric with ordinary menthone. Carvotanacetone yields corresponding compounds carvomen- thol and carvomenthone. The physical properties of the isomers, thujone, isothujone and carvotanacetone are given by Wallach as follows :— Tiemann gives the boiling point of thujone (tanacetone) as 203° and of carvotanacetone as 230°. Terpineol, C10H17OH.—The substance usually known in commerce under this name, which now plays an important part in the preparation of artificial perfumes, has long been Thujone . Isothujone Carvotanacetone Boiling Point. Specific Gravity. Refractive Index. 200°-201° -912 1-4503 231°-232° -9285 1-48217 228° -9373 1-48350