Carveol carvone

As with many of the enhancers described above, a synergistic effect for terpene efficacy has also been shown when PG was used as the vehicle [54] with this cosolvent, enhancer activities for carveol, carvone, pulegone, and 18 cineole rose approximately fourfold, explained by improved partitioning of the terpene into the stratum corneum. Enhancement using terpenes in PG has recently been revisited for haloperidol delivery through human skin [55,56],... 

Further n.m.r. data have been published on isomeric menthyl cf. Vol. 7, pp. 5, 29) and carvomenthyl alcohols and some derivatives.N.m.r. data include [Eu(dpm)3] methyl shift assignments in the menthols, the menthones, two carvomenthols, the isopulegols, the carveols, carvone, carvotanacetol, and carvotanacetone, together with the relevant acetates, and an analysis of... 

Yomogi alcohol, aitemlsia alcohol, davanone, lyratol + lyratyl acetate, chrysanthenol, carveol, carvone, dihydrocarvone, terpinene-4-ol, y-campholenol, myrtenol, p terpineol, 4-thujene-2-a-yl-acetate, carveyl acetate, fkcubebene, juniper camphor, thymol, P-terpenyl acetate, linalool Sabinene, germacrene D... 

Bouwmeester HJ, Davies JAR, Toxopeus H, Enantiomeric composition of carvone, limonene, and carveols in seeds of dill and annual and biennial caraway YiLnexies, JAgricFood Chem 43 3057-3064, 1995. 

Acylation of limonene at the disubstituted double bond is favoured by a factor of 2.3 over reaction at the trisubstituted double bond using acetyl hexachloroan-timonate. Mixed alkylcuprate alkylation of tricarbonylcyclohexadienyliron salts has been used to synthesize the a-phellandrene tricarbonyliron complex. Dichlorocarbene addition to limonene in the presence of 1,4-diazabicy-clo[2,2,2]octane is almost 100% stereoselective at the trisubstituted double bond (no yield given) (cf. Vol. 6, p. 31) in contrast to dibromocarbene addition to carvone (Vol. 7, p. 34), dichlorocarbene addition to the carveols is not regio-specific. ... 

Limonene (92) is the most widely distributed terpene in nature after a-pinene [68]. The (+)-isomer is present in Citrus peel oils at a concentration of over 90% a low concentration of the (-)-isomer is found in oils from the Mentha species and conifers [26]. The first data on the microbial transformation of limonene date back to the sixties. A soil Pseudomonad was isolated by enrichment culture technique on limonene as the sole source of carbon [69]. This Pseudomonad was also capable of growing on a-pinene, / -pinene, 1-p-menthene and p-cymene. The optimal level of limonene for growth was 0.3-0.6% (v/v) although no toxicity was observed at 2% levels. Fermentation of limonene by this bacterium in a mineral-salts medium resulted in the formation of a large number of neutral and acidic products. Dihydrocarvone, carvone, carveol, 8-p-menthene-1,2-cw-diol, 8-p-menthen-1 -ol-2-one, 8-p-menthene-1,2-trans-diol and 1 -p-menthene-6,9-diol were among the neutral products isolated and identified. The acidic compounds isolated and identified were perillic acid, /Msopropenyl pimelic acid, 2-hydroxy-8-p-menthen-7-oic acid and... 

As mentioned before, a Pseudomonas incognita was isolated by enrichment technique on the monoterpene alcohol linalool that was also able to grow on geraniol, nerol and limonene [36]. The metabolism of limonene by this bacterium was also investigated [37]. After fermentation the medium yielded as main product a crystallic acid, perillic acid, together with unmetabolised limonene, and some oxygenated compounds dihydrocarvone, carvone, carveol, p-menth-8-en-1 -ol-2-one, p-menth-8-ene-1,2-diol or p-menth-1 -ene-6,9-diol (structure not fully elucidated) and finally / -isopropenyl pimelic acid. 

The fungal bioconversion of limonene was further studied [82]. Penicillium sp. cultures were isolated from rotting orange rind that utilised limonene and converted it rapidly to a-terpineol. Bowen [83] isolated two common citrus moulds, Penicillium italicum and P. digitatum, responsible for the postharvest diseases of citrus fruits. Fermentation of P. italicum on limonene yielded cis- and frans-carveol (93) (26%) as main products, together with cis- and from-p-mentha-2,8-dien-l-ol (110) (18%), (+)-carvone (94) (6%), p-mentha-1,8-dien-4-ol (111) (4%), perillyl alcohol (100) (3%), p-menth-8-ene-1,2-diol (98) (3%), Fig. (17). Conversion by P. digitatum yielded the same products in lower yields. The two alcohols />-mentha-2,8-dien-1 -ol (110) and p-mentha-1,8-dien-4-ol (111) were not described in the transformation studies where soil Pseudomonads were used [69]. 

Limonene is the major monoterpene in orange oil. This is a colorless and odorless compound at high purity. However, it rapidly oxidizes to carveol and carvone in the presence of air. Under acidic conditions, a-terpineol, P-terpineol, and y-terpineol are also produced. Many of the impurities present in limonene have much higher odor potencies. These odor potent compounds can be perceived as limonene odor . 

The pyridinium chlorochromate-on-alumina reagent (7.5 g, 6.1 mmol, Section 4.2.18, p. 426) is added to a flask containing a solution of carveol (0.60 g, 3.8 mmol) in hexane (10 ml). After stirring for 2 hours, the solution is filtered, and washed with three 10-ml portions of ether. The combined filtrates are evaporated and vacuum distilled to afford carvone yield 0.54 g (93%), b.p. 104°C/11 mmHg. Gas-liquid chromatography analysis is on a column of 10 per cent Carbowax 20M supported on 60-80 mesh Chromo-sorb W. 

This method is of value when the alcohol is readily available from natural sources, or when it can be prepared, for example, by the reaction of an alkenyl-organometallic reagent with an aldehyde. An example of the former is the oxidation of the terpenoid alcohol carveol to carvone (Expt 5.88) using pyridinium chlorochromate-on-alumina reagent. 

Ce4+ is easily exchanged on resins such as Nation. Ce-Nafion catalyzed the oxidation of carveol to carvone with t-BuOOH as the oxidant no data characterizing leaching were provided (59). CeC>2 on AI2O3 was used as a solid catalyst for the cooxidation of cyclohexane and cyclohexanone. Products are dibasic acids and e-caprolactone. It was claimed that in water-free reaction conditions, Ce is not eluted from the solid (342). 

Examples of the use of chromium(VI) reagents to effect the allylic oxidation of alkenes to give a,3-unsaturated carbonyl compounds are very common in the literature. "-" The reaction was first report by Treibs and Schmidt" for the allylic oxidations of a-pinene to verbenone and veibenol, of dipentene to carvone and carveol, and of cyclohexene to cyclohexenol and cyclohexenone, using a solution of chromium trioxide in a mixture of acetic anhydride and carbon tetrachloride. However, yields were low and no synthetic use of this observation was made. 

Certain racemic ketones can be resolved kinetically through asymmetric hydrogenation. When racemic carvone is hydrogenated using an (5)-BINAP/Ru complex, / ,/ )-DPEN, and KOH, it gives, at 54% conversion, the starting (5)-carvone in 94% ee (46%) together with (l/ ,5 )-carveol in 93% ee (50%) and some other minor alcohols (3.7%) (eq 8). The extent of the enantiomer differentiation ability, ifast/ siow, is calculated to be 33. 

Maruoka has successfully developed a highly accelerated Oppenauer oxidation [31,32] system using a bidentate aluminum catalyst [29]. This modified, catalytic system effectively oxidizes a variety of secondary alcohols to the corresponding ketones as shown in Sch. 9. For example, reaction of (2,7-dimethyl-l,8-biphenylene-dioxy)bis(dimethylaluminum) (8, 5 moI%) with carveol (14) at room temperature in the presence of 4-A molecular sieves, and subsequent treatment with pivalaldehyde (3 equiv.) at room temperature for 5 h yielded carvone (15) in 91 % yield. Under these oxidation conditions, cholesterol (16) was converted to 4-cholesten-3-one (17) in 75 % yield (91 % yield with 5 equiv. t-BuCHO). 

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