Cedrene oxide

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, ner-ol 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, slightly ambergris-like odor, can be prepared by treatment of -caryophyllene with organic peracids. a-Cedrene oxide [11000-57-0] is another wood-fragrance compound, which can be easily prepared by epoxidation of cedarwood oil hydrocarbons. 

Semmler and Risse have studied the oxidation of cedrene by means of ozone. They obtained the keto-acid, Cj Hj Oj, which on further oxidation either by means of bromine or nitric acid yields a dicarboxylic acid. 

Hypoiodite reaction [1, 552, end of page]. Cedrene (1) is oxidized to cendranoxide (2) in 50% yield by lead tetraacetate in combination with iodine.503 The oxide is obtained only in traces when lead tetraacetate is used alone. 

Carbon suboxide, 52 Carbonylation, 148, 149, 216 Carbonyl chlorofluoride, 48, 54 Carbonyl cyanide, 60-61 N,N -Carbonyldiimidazole, 61 1,1-Carbonyldi-l,2,4-triazole, 61 N-Carbonylsulfamic acid chloride (N-Carbonylsulfamyl chloride), 61 Carboxamides, 270 Carboxamine-N-sulfochlorides, 70 p-Carboxybenzenediazonium chloride, 62 p-Carboxybenzenesulfonazide, 62 Carboxylation, 15, 16 Carboxylic acid anhydrides, 133 Carboxylic acid N,N-dimethylamines, 153 Carboxylic anhydrides, 409-410 p-Carboxyphenylhydrazones, 62 Cardenolides, 130, 131 (S-Carotene, 19 /-Carvone, 451, 452 i//-Caryophyllene, 149, 150 Catechol, 65, 233 Catechol amines, 159 Catechyl phosphorus tribromide, 63 Catechyl phosphorus trichloride, 63 Cis-Cecropia juvenile hormone, 261 Cedrene, 234, 235 a-Cedrene, 349 /3-Cedrene, 349 Cendranoxide, 234, 235 Cephalosporin C, 48 Ceric ammonium nitrate, 63-65 Ceric sulfate. 65 Cesium fluoride, 346 trans-Chalcone oxide, 422 Chalcone phenylhydrazones, 257, 258 Chalcones, 406 Chloramine, 65-66, 69 Chloranil, 66-67, 113, 116, 401,454... 

Takigawa, H., H. Kubota, H. Sonohara, M. Okuda, S. Tanaka, Y. Fujikura, and S. Ito. 1993. Novel allylic oxidation of a-cedrene to sec-cedrenol by a RJiodococcus strain. Appl. Environ. Microbiol. 59 1336-1341. 

Carvone oxide CarvyI acetate L-CarvyI acetate Caryophyllene alcohol Caryophyllene alcohol acetate Cascara (Rhamnus purshiana) extract Castoreum Cedarwood oil Cedrene a-Cedrene 8-Cedrene epoxide Cedrenol... 

Spathulenol, juniper camphor, chamazulene, P-caryophyllene, P-caryophyllene alcohol, caryophyllene oxide, chrysartemin A+B, a-cedrene, elemol, clovandiol, eudesmanolides... 

Nicotiana. The comprehensive study mentioned already above (see Sect. 7.2.1.1) demonstrated also the occurrence of Cj VOCs, i.e., sesquiterpenes e.g., p-caryophyllene (Fig. 7.4), a-cedrene, different famesenes (Fig. 7.4), a-humulene and oxygenated sesquiterpenes (e.g., different cis-trans isomers of nerolidol, far-nesal, and famesol, as well as caryophyllene oxide) (Raguso et al. 2003). Further constitutive sesquiterpenoids from Nicotiana will be discussed below in connection with phytoalexins of this genus. 

Eousset has studied the oxidation products of cedrene, from which he obtained the ketone cedrone, CijHj O, by means of chromic acid. On reduction this yields an alcohol, isocedrol, isomeric with cedrol. 

In addition. Green and Pettus have reported efficient syntheses of a-cedrene, a-pipitzol, and ec-cedrenol on the basis of a novel domino oxidative dearomatization-intramolecular [5+2] cycloaddition-acetic acid addition reaction [96]. Indeed, the key step of the syntheses began with the oxidative dearomatization of ortAo-(pent-4-enyl)-phenols 92, followed by an intramolecular [5+2] cycloaddition of the respective phenoxonium intermediate across the tethered olefin to afford the corresponding tricyclo-[5.3.1.0 ]-undecanes, which finally added acetic acid to provide the final products 93 in low to good yields, as shown in Scheme 20.40. The benzylic... 

Stereocenter effectively guided the formation of the first two stereocenters during the [5+2] reaction. The sequence then terminated with the selective incorporation of acetic acid to generate a third stereocenter, setting it apart from other previous cationic [5+2] reactions. It must be noted that this oxidative dearomatization-induced cascade reaction is unique as it proceeds in the absence of para-oxygen substituent. Starting from tricyclic product 93, the three members of the cedranoid family, a-cedrene, a-pipitzol, and ec-cedrenol, were easily achieved in several supplementary steps. 

V-G-8.3. Reaction Kinetics of the Atmospheric Oxidation of Acetyl Cedrene [(3R-(3aJab,7b,8aa))-l-(2,3,4J,8,8a-hexahydro-3,6,8,8-tetramethyl-lH-3a, 7-methanoazulen-5-yl)ethan-l-one ]. 

The atmospheric lifetime of acetyl cedrene is determined primarily by reaction with OH during the day. For [OH] = 2.5 x 10, the lifetime is about 1.4 h. There have been no studies of the products of its oxidation or the photodissociation lifetimes. 

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