Rose oil components

In another variation, the intermediate aldol product 64, with an extra hydroxy group in the y-position, was used to construct the furan ring of rosefuran (65), a trace component of rose oil (Scheme 6.56) (285). Here, the reaction of the nitropentene derivative 61 with crotyl acetate (62) afforded the 3,4,5-trisubstituted isoxazoline (63) in moderate yield. Removal of the acetyl group by saponification of the cycloadduct, subsequent demasking of the aldol moiety using Mo(CO)6, and exposure of the ketodiol (64) to acid gave the target compound 65 (285). 

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,... 

In addition to the major components mentioned above, rose oil also contains a number of components which, although present in low concentrations, contribute to the characteristic fragrance [725-73 lb]. Among these are /3-damascenone (see p. 68) and rose oxide (see p. 143). 

The common names of these intermediates derive from the sources from which they were first isolated. Geraniol, a component of rose oil, has the aroma of geraniums, and farnesol is an aromatic compound found in the flowers of the Farnese acacia tree. Many natural... 

Examples of monoterpenes include the linear aldehyde citral, which is found in many essential oils, and the (cis) alcohol geraniol, a major component of oil of geranium. Cyclic monoterpenes include limonene, menthol, pinene, camphor, and carvone, major components of lemon oil, mint oil, turpentine, camphor oil, and caraway oil, respectively. Sesquiterpenes include farnesol, a component of rose oil, and bisabolene, a component of Bisabol myrrh. The diterpenes include phytol, a component of chlorophyll, and vita-... 

The damascones are a group of materials related to the ionones, but in which the enone unit is transposed. They are components of rose oils and have very intense fruity-floral odours. The damascenones, which contain a second double bond in the ring, are also very much sought after. One synthesis of a-damascone from methyl a-cyclogeranate is shown in Scheme 4.40. A double Grignard addition gives the tertiary alcohol. Heating of this in the presence of base, to prevent elimination... 

Vomifoliol (97) isolated from Rauwolfia vomitoria appears to be a degradation product of abscisic acid and possibly a precursor of theaspirone. Damas-cenone, a minor component of Bulgarian rose oil, was shown to be the cross-conjugated isomer (98) of dehydroionone. A tetrahydro-damascenone was prepared by treating a-ionone-7,8-oxide with hydrazine. ... 

Figure 10.8 shows three monoterpenoid alcohols geraniol (10.16), citronellol (10.21) and linalool (10.22) all of which have been mentioned earlier as being key fragrance ingredients which can be obtained from natural sources. Geraniol is one of the character impact components of rose but it is only present in rose oils to the extent of about 30%. Much... 

Some natural products containing a furan ring have an intense odour, e.g. 2-furylmethanethiol 27, a component of coffee aroma, rose furan 28, a component of rose oil, and menthofuran 29, which occurs in peppermint oil. The compounds 28 and 29 are reminiscent of terpenoid structures ... 

CnH.gO, Mr 190.29, oil, bp. (1.7 kPa) 116-118°C. Component of Bulgarian rose oil, obtained from Rosa damascena. /3-D. is only present to 0.05% in this oil but is mainly responsible for the rose-like fragrance. j8-D. is an essential component of perfumes and gives them fresh and brilliant notes. 

At the beginning of the 1960s, Ervin Koviits (1927-2012) found that rose oil consists of at least 275 components (which led to certain disillusionment). These substances, characteristic of rose scent, were still unknown, and might, in an unfavomable case, be present in only trace amounts. The first important component to be discovered was rose oxide [27], a cyclic monoterpene ether, at a concentration of 0.5%. Rose oxide has an unpleasant smell, reminiscent of mineral oU. At high dilution however, it exudes a scent of beautifid freshness and a nuance reminiscent of green leaves. 

Component Proportion in rose oil (%)) Scent threshold (ppb) Units of scent Relative proportion of scent units (%)... 

Cohobation Some oils are partially soluble in water and so when the oil separates from the water distillate a portion of the oil still remains in the aqueous fraction. This typically happens with rose oil as one of the important components is phenyl ethyl alcohol, which remains in the water after separation. Thus, phenyl ethyl alcohol and any other water-soluble components must be either distilled from the distillate or extracted by some other means and added back to the separated oil. This process has been given the name of cohobation. 

Anxiolytic proprieties were observed in rats with the plus maze model after 7 min rose oil inhalation this is the only report of inhaled effects in animals after a short period of inhalation, although the procedure of leaving four cotton balls embedded with 2 mL of EO lacks standardization (Almeida et al. 2004). As previously mentioned, inhaled cedrol was shown to be sedative in rats (Kagawa et al. 2003), and the inhalation of a volatile mixture from the TCM SuHeXiang Wan composed of 21.4% borneol (29), 33.3% isoborneol (30), 5.9% eugenol (4), and other minor components delayed the appearance of PTZ-induced convulsions suggesting GABAergic modulation (Koo et al. 2004). 

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