Essential oils rose oxide

Essential oils are organic compounds derived from flowers, seeds, leaves, roots, resins, and citrus fruits. The structures of many fragrant compounds have been studied, and processes for making these valuable compounds in a laboratory have been developed. There are now approximately 5000 synthetically produced chemicals that are available to a perfumer. These chemicals include vanillin, rose oxides, and the damascenes, or rose ketones. 

Cyclic ethers used as fragrances include a number of terpenoid compounds. Some of them, such as 1,4-cineole [470-67-7] and 1,8-cineole, occur in essential oils in significant quantities. Others are only minor components examples are rose oxide, nerol oxide [1786-08-9], and rose furan [15186-51-3], which contribute to the specific fragrance of rose oil. Caryophyllene oxide [1139-30-6], which has a woody,... 

Phenylethyl alcohol is prepared by reduction of ethyl phenyl-acetate with sodium in absolute alcohol by hydrogenation of phenylacetaldehyde in the presence of a nickel catalyst or by addition of ethylene oxide or ethylene chlorohydrin to phenylmagnesium bromide, followed by hydrolysis. Phenylethyl alcohol also occurs naturally in a number of essential oils, especially rose oil. 

The occurrence and syntheses of rose oxides, dihydrorose oxides, rosefuran, and nerol oxides, together with related compounds, have been reviewed. The structure of a cyclic monoterpenoid ether from Artemisia tridentata, which is related to the santolinyl monoterpenoids, has been confirmed (c/. Vol, 7, p. 20) as (227) and renamed artemiseole (c/. Vol. 8, p. 58 for an incorrect structural deduction).Interestingly, another new component of A. tridentata, the (3S)-diastereoisomer of (74), with formic acid yields (227) in contrast to (74) which yields the acyclic aldehyde (228). ° It is possible that some of the 31% of unidentified components in the essential oil of A. annua may correspond to these new compounds.The quinone (229) has been isolated from Lithospermum erythrofhizon, and further details on the presence of aeginetolide in Aeginetia indica have been published. 

Matsuda, H. Yamamoto, T. Kanisawa, T. Synthesis and Odor Properties of Optical Isomers of Rose oxide and Dihydrorose oxide, in The 13th International Congress of Flavours, Fragrances and Essential Oils. 1995. Istanbul, Turkey, pp 85-91. 

Oil of thyme contains p-myrcen-8-ol derived from p-myrcene, and (i )-(-)-ipsdienol as well as its non-chiral regioisomer is not only the aggregation pheromone of the bark beetle Ips confusus, but also the fragrance of the blossoms of many orchids. Terpenoid pyran derivatives include diastereomeric rose oxides [(2/ ,4/ )-trans- and (2S,4R)-cis-] as well as racemic nerol oxide, which essentially contribute to the pleasantly flowery green smell of the Bulgarian oil of rose... 

Numerous other ethers containing pyran or furan rings are formed by the dehydration of aliphatic diols (e.g. linalool oxides, rose oxide or nerol oxide) and are components of many essential oils. For example, the furanoid 2R,5R)- E)- and (2J ,5S)-... 

Z)- and pyranoid 3R,6R)- Z)- and (3S,6S)-(Z)-linalool oxides (8-32) are odorants of jasmine tea, aromatic wines, elderberry bush flowers and linden honey. In grapes, (-)-(Z)-rose oxide from (-)-citroneUol is analogously produced. Rose oxide is also a component of rose and geranium essential oils (8-32). Nerol oxide in rose oil is a racemate. 

Rose oxide is found in a number of essential oils, but particularly those of rose and geranium. It is used to give dry, green, and rosy top-notes to fragrances. Racemates and optically pure (both laevo- and dextro-) forms are commercially available and used in fragrances. The homochiral products, especially the laevorotatory ones, command much higher prices than does the racemate. 

Figure 12 SPME (PDMS/DVB fiber) in essential oil analysis. Direct injection of rose oil volatiles compared with tiie components obtained by fiber extraction (TIC). Peak identities are as follows 1, a-pinene 2, p-pinene 3, myrcene 4, cis-rose oxide 5, trans-mse oxide 6, linalool 7, citronellol 8, nerol 9, geraniol 10, 2-phenylethyl alcohol 11, nonadecane 12, (Z)-9-nonadecene 13, methyl eugenol 14, eugenol 15, famesol.

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