Cineole ketone

Cyclic ketals (potential cosmetic ingredients) were obtained in excellent yields from a cineole ketone under the action of microwaves in solvent-free conditions or in toluene. The results reported compared very favorably with those obtained by use of conventional heating (Eq. (23) and Tab. 3.9) [76]. 

Tab. 3.9 Synthesis of ketal from cineole ketone and propylene glycol (Ri = CH3 R2 H).

According to all reliable observations, the oxygen atom in cineol does not possess alcoholic, ketonic, aldehydic, or acid functions. Apparently it is quite indifferent, which accounts for the isolated nature, chemically speaking, of the compound. In commerce, this body finds considerable employment under its name, eucalyptol. 

Artemisia ketone (2) Artemisinic alcohol (3) Arteannuin B (4) 1,8-Cineole (5) Camphor (6) Fig. 2. Examples of some secondary metabolites isolated from Artemisia annua. 

Roman mugwort Artemisia pontica L. Artemisia ketone (23-46), a-thu-jone (14-30), 1,8-cineole (12-23)... 

Important aroma compounds of black currant berries have been identified mainly by GC-O techniques by Latrasse et al. [119], Mikkelsen and Poll [115] and Varming et al. [7] and those of black currant nectar and juice by Iversen et al. [113]. The most important volatile compounds for black currant berry and juice aroma include esters such as 2-methylbutyl acetate, methyl butanoate, ethyl butanoate and ethyl hexanoate with fruity and sweet notes, nonanal, /I-damascenone and several monoterpenes (a-pinene, 1,8-cineole, linalool, ter-pinen-4-ol and a-terpineol) as well as aliphatic ketones (e.g. l-octen-3-one) and sulfur compounds such as 4-methoxy-2-methyl-butanethiol (Table 7.3, Figs. 7.3, 7.4, 7.6). 4-Methoxy-2-methylbutanethiol has a characteristic catty note and is very important to blackcurrant flavour [119]. 

Hedychium coronarium Koen. Shan Ren (Ginger lily) (flower, rhizome) Sesquiterpenes, phenols, aldehyde, ketone, 1,8-cineole, camphene, beta-pinene.60-195 Stimulant. 

Turmeric owes its aromatic taste and smell to the oil present in the rhizome. Analysis of the oil, obtained by steam distillation of the powdered rhizome, followed by fractional distillation and derivatization, shows that the components are a mixture of predominantly sesquiterpene ketones and alcohols (Kelkar and Rao, 1933). The residue on steam distillation yields mainly sesquiterpene alcohols. Besides these major components, they have also identified a mixture of low-boiling terpenes, c/-sabinene, a-phellandrene, cineole, borneol and the higher-boiling sesquiterpene, zingiberene, in substantial amounts (25%). 

Essential oil from A. annua is another active research interest as it could be potentially used in perfume, cosmetics, and aromatherapy. Depending on its geographical origin, the oil yield in A. annua ranges from 0.02% to 0.49% on a fresh weight basis and from 0.04% to 1.9% on a dry weight basis. The major components in the oil were reported to be artemisia ketone (80), isoartemisia ketone (81), 1,8-cineole (82), and camphor (83) (Structure 5-5). GC/MS was employed to analyze the chemical composition in the essential oil more than 70 constituents have been identified. For more detailed information on the oil composition of essential oil from A. annua, the readers are referred to Refs. 65, 66 and 72-81. 

Karamenderes et al. [67] reported the composition and antimicrobial activity of the essential oils obtained from Achillea millefolium L. subsp. pannonica (Scheele) Hayek, Achillea millefolium subsp. millefolium, Achillea arithmifolia Waldst Kitt and Achillea kotschyi Boiss. subsp. kotschyi, four Achillea species from Turkey. 1,8-cineole, Fig. (2), artemisia alcohol and ascaridole were identified as major components. The essential oils showed antibacterial and antifungal effects even with low concentrations. The essential oil of the flowering tops of another Achillea species, Achillea fragantissimum (Forsk.) Sch. Bip growing in Sinai, was analyzed [68]. Santolina alcohol, a- and P-thujone, Fig. (5) and artemisia ketone account for approximately 80% of the oil. The oil showed marked antimicrobial activities against Escherichia coli. Bacillus subtilis and Staphylococcus aureus. 

Artemisia afra Willd. (African wormweed) The major components in A. afra oil (1.5%) from semi-dried leaves were 1,8-cineole (67%), terpinen-4-ol (7%) and bomeol (5%) (39). The oil from Zimbabwe contains mainly artemesia ketone (6.3-41.9%) and 1,8-cineole (0.1-27.9%) (40). In East Africa the aerial parts of A. afra are used to treat indigestion as well as sore throats and fever in children. The roots are used for treating intestinal worms and the leaves are chewed as emetic (35). In South Africa fumes from boiled leaves are inhaled for blocked nasal passages (41). 

Two new preparations of 1,8-cineole (553) [the biogenesis of which from geraniol (25) in Rosmarinus officinalis has been elucidated ] have been recorded. A Diels-Alder adduct 625 (R = Me) of methyl vinyl ketone and isopropenyl methyl ketone was converted to the diazoketone (R = CH = N2) with diethyl oxalate/base, then toluenesulfonyl azide, and treatment of the latter with [Rh(OAc)2]2 in methylene chloride at room temperature for five minutes converted it in very high yield to the tricyclic compound 626. Lithium dimethylcuprate then yielded the ketone 627, conversion of which to 1,8-cineole (553) was known.The other 1,8-cineole synthesis was a by-product of an observation which enabled the two stereoisomers of limonene 1,2-epoxide to be separated. The cjs-epoxide 549 was brominated to stereoisomers of a dibromocineole 628, under conditions when the rran.s-epoxide did not react, and could be distilled pure afterward. The dibromo compound 628 yielded 1,8-cineole (553) with tributyltin hydride. 

The ketone 629 has been isolated from peony flowers. It had already been synthesized several times for example, by hydroboration of the enamine 630 of the isomeric ketone 627, then Cope elimination of the iV-oxide 631 of the amino alcohol. Chromyl acetate oxidation of 1,8-cineole (553) led first to 629 further oxidation gave diketones. Aspergillus niger also gave some 629, although the main products were the corresponding alcohols. ... 

Essential oil composition studies of interest concern Mentha rotundifolia [—85% piperitenone epoxide (26)], Artemisia afra (cineole, artemisia ketone. 

Sesquiterpenes ketone (65% e.g. turmerone), zingiberene (about 25%), pliellandrenc, sabinene, borneol and cineole 3%-4% pigments curcumin, monodemethoxy curcumin, bi.sdemethoxycurcumin, di-p-ccmmaioylmethane... 

Oxidation photocatalyzed by polyoxometalates [66k] has been applied to the fimctionalization of 1,8-cineole (structure IX-10) [661], widely distributed in the plant kingdom. The photooxygenation of IX-10 gave a mixture of ketones and alcohols which were transformed by the subsequent action of pyridinium chloro-chromate into 5- and 6-keto derivatives in the ratio IX-11 IX-12 = 2.5 1. A laser flash photolysis study of the mechanism has been carried out for the deca-tungstate anion catalyzed reaction [66m]. 

Thujone was discovered by E. Schweizer. C. VolckeP discovered carvone in carraway seed oil, and cineol in wormseed oil. Carvone was shown to be a ketone related to limonene by H. Goldschmidt and R. Ziirrer. Linalool was discovered by distilling coriander oil by A. Kawalier and prepared from linaloe wood (licari kamali) by H. Morin.Geraniol was discovered by O. Jacobson in oil of palma rosa. F. W. Semmler " showed that it is an olefinic terpene with an open carbon chain. Menthone was obtained from oil of peppermint by R. W. Atkinson and H. Yoshida. (Menthol was known much earlier and was analysed by Dumas in 1832.) G. Bouchardat and R. Voiry obtained terpineol from essential oils. Citronellal (an aldehyde) was discovered by F. D. Dodge.2 ... 

Camphor-cineole-bomeol, P-thujone, chrysanthenone, dihydrocarvone P-thujone, chrysanthei l acetate, camphor + thujone Thujone, camphor, bomeol, bornyl acetate, chrysanthenol, chrysanthenyl acetate, l,8 ineole, a-terpineol Chrysanthenyl acetate, isopinocamphone, not identi ed sesquiterpene Artemisia ketone, chrysanthenol + chrysanthenyl acetate, lyratol + lyratyl acetate, p-thujone... 

Cineole, artemisia ketone, camphor, a-thujone Chrysanthenyl acetate... 

P-Thujone, camphor, artemisia ketone, umbellulone, chrysanthenyl acetate, chrysanthenone, chrysanthenol, 1,8-cineole a-Pinene + triciclene, P pinene + sabinene, 1,8-cineole, y-terpinene, artemisia ketone, thujone, camphor, trmbelltdone, borneol, humulenol... 

---