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  • Structure-odor correlation  (5)
  • Essential oil  (4)
  • 1
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1205-1212 
    ISSN: 1434-193X
    Schlagwort(e): New tricyclic sesquiterpene alcohols ; Natural products ; Essential oil ; Compositae ; Odoriferous substances ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The strong patchouli-like and woody smelling essential oil of the rhizomes of Echinops giganteus var. lelyi C. D. Adams (Compositae) contains only sesquiterpenes, which are mainly triquinanes. Besides the known tricyclic compounds, silphiperfol-5- (1, 3) and -6-ene (4), modhephen-2-ene (5), α- (6) and β-isocomene (7), silphiperfolan-7β-ol (12), presilphiperfolan-8-ol (13), silphiperfol-6-en-5-one (14) and 7-epi-silphiperfolan-6β-ol (20), the following compounds, three of which (15, 17, 18) have new skeletons, were found, for the first time, occurring naturally: presilphiperfol-7-ene (2), cameroonan-7-ol (15), an 11(7→8)-abeo-presilphiperfolan-7-ol, prenopsan-8-ol (17), a 1(8→7)-abeo-cameroonan-8-ol, and nopsan-4-ol (18), a 3(4→8)-abeo-prenopsan-4-ol, three diastereomers of silphiperfolan-6-ol (19, 21, 22), modheph-2-en-8-ol (23) and silphiperfola-4,7(14)-diene (24). All structures were elucidated by NMR spectroscopy. A biogenetic pathway from a presilphiperfolane cation C to the cameroonane K, prenopsane L and nopsane M cations is shown. Cameroonanol (15) and prenopsanol (17) are the main contributors to the fragrance of the total oil.
    Materialart: Digitale Medien
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  • 2
    ISSN: 0947-3440
    Schlagwort(e): Rose furan ; Perillene ; Furans ; Thiophenes ; Structure-odor correlation ; Odoriferous substances ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Starting from 3-bromofuran (1) or 3-bromothiophene (2) via alkylation in 2-position (→ 3-8) followed by the corresponding second alkylation in 3-position, we obtained rose furan (9), rose thiophene (10), and their analogs 11-16. From the α,β-unsaturated esters 17-20 by hydrogenation (→ 21-24), DIBAH reduction (→ 25-28), and Wittig reaction, perillene (29), thioperillene (30), and their analogs 29-36 were obtained. Olfactory evaluation showed that the difference between the furans and thiophene derivatives is remarkably small, particularly for perillene (29) compared with thioperillene (30), and their analogs. Also the influence of position and structure of the side chain is lower than expected within the compared compounds 9-36.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1989 (1989), S. 307-308 
    ISSN: 0170-2041
    Schlagwort(e): Essential oil ; Phoebe oil ; Lauraceae ; Oreodaphne porosa ; Sesquiterpenes ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: From the essential oil of Oreodaphne porosa (commercial “Phoebe oil”) a sesquiterpene alcohol with a new carbon skeleton, oreodaphnenol (1), could be isolated. The structure and relative stereochemistry were deduced from detailed NMR studies and by degradation to the ketone 2.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
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  • 4
    ISSN: 0170-2041
    Schlagwort(e): Artemisia laciniata ; Sesquiterpene alcohols, tricyclic ; Structure-odor correlation ; (R)-(+)-Pulegone ; 1,4-Grignard reaction ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The new sesquiterpene alcohols silphiperfol-5-en-3-ol [( - )-1a] and the corresponding 7-epi compound (+)-1b, important constituents of the essential oil of Artemisia laciniata have been synthesized in 13 steps by starting from (R)-(+)-pulegone (6) in an overall yield of 8%. The key reaction is the coppercatalyzed 1,4-Grignard addition of the iodo acetal 34 to the enone (+)-4 in the presence of TMSCI and TMEDA to give the silyl ether 38. Hydrolysis with spontaneous aldol cyclization and dehydration leads to the silphiperfolenones (+)-2a, b which are separable by flash chromatography. The reduction with L-selectride® gives the alcohols ( - )-1a and (+)-1b which are identical in all physical properties with the isolated natural compound. With LiAlH4 the diastereoisomers 42a, b are formed. Olfactive evaluation of the isomers ( - )-1a and (+)-1b has shown that the odor of the naturally occurring mixture of 1a, b with the descriptors woody, ambergris, slightly camphoraceous is correctly assigned. ( - )-1a represents the more woody and camphoraceous, (+)-1b the more animal facette of ambergris. The odor of rac-1a, b of the diastereoisomers 42a, b and of the ketones (+)-2a, b is also described as well as that of the tris-nor-silphiperfolene derivatives 29-31.
    Materialart: Digitale Medien
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  • 5
    ISSN: 0170-2041
    Schlagwort(e): Artemisia salsoloides ; Essential oil ; 4-Oxogeranyl acetate ; Furomyrcenol ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: From the essential oil of Artemisia salsoloides the oxygenated monoterpenes 1, and 3-8 could be isolated. The easy formation of the hydroperoxide 2 from 1 suggests a biogenetic pathway from geraniol/nerol to 3. By comparison, the synthesized 8 exhibits mushroom and celery odor, typical of fractions of the A. salsoloides oil containing 8.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1991 (1991), S. 19-25 
    ISSN: 0170-2041
    Schlagwort(e): Megastigmatrienone analogues ; 4,4,7a-Trimethylinden-2-one ; Structure-odor correlation ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Structure-Odor Correlation, XIII1). - Synthesis and Olfactive Properties of Megastigmatrienone AnaloguesThe key compound 9 was readily prepared in larger quantities by an improvement of a known procedure. Addition of carbanions to the unprotected ketone 9 gives the hydroxy ketones 16-21 via the acetals 10-15. Dehydration of 16-20 furnishes the dienones 2-6 while 7 is available in fair yield via the acetoacetate 21. Through intramolecular cyclization also the ester 26 is formed which affords with NaOH the keto ester 29 by a retro-Michael reaction. The diketone 28 (obtained from 29) can be reduced selectively to give 30, dehydration of which leads to 31/32. - The odor of 2 (camphor, sweet, wood, plum) is the olfactive link between the odor of isophorone and megastigmatrienone (A). Elongation of the alkyl group (→ 3-5) leads first to a herbaceous, then to a leathery note. The one-diene-one 7 smells unexpectedly weak. For the very strong odor (tobacco, wood, plum) of A obviously the total osmophor is responsible including the unsaturated side chain.
    Materialart: Digitale Medien
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  • 7
    ISSN: 0170-2041
    Schlagwort(e): Essential oil ; Artemisia salsoloides ; Compositae ; Sesquiterpene, new skeleton of ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: From the essential oil of Artemisia salsoloides a sesquiterpene epoxide with a new carbon skeleton, salsolene oxide (1), could be isolated. The structure and relative stereochemistry were deduced from extended NMR studies.
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1990 (1990), S. 1029-1036 
    ISSN: 0170-2041
    Schlagwort(e): 7-Oxanorbornane, 1,4-dimethyl- ; Furan, 2,5-dimethyl- ; Diels-Alder reaction ; Structure-odor correlation ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The 7-oxanorbornanes 17-19 are prepared by Diels-Alder reaction of 2,5-dimethylfuran (1) and 2-isopropyl-5-methylfuran (2) with 2-chloro- (3) or 2-acetoxyacrylonitrile (4). The adducts 5-10a,b are hydrogenated (→ 11-16a, b) and subsequently hydrolyzed. From 1 and acrylonitrile (21) the stereoisomers 25a, b can be obtained via 23a, b in various ratios, depending on the reaction conditions. The Grignard reaction of the exo nitrile 25a with MeMgI or iPrMgI gives the exo ketones 27a and 28a. In the case of the endo nitrile 25b the same reaction favors the formation of side products. LiAlH4 reduction of 17, 26b, 27b, and 28a yields the 7-oxanorbornanyl alcohols 29b-31b and 32a.  -  The fragrance of the ketones 18 and 19 is very similar to that of the substructures 1,4-cineol and menthone. The smell of ketones 27 and 28 as well as of the alcohols 29b-31b is weak. Odor quality and strength of the alcohols 32a′, a″ are determined by their ability to form more or less easily an intramolecular hydrogen bond leading to a rigid conformation which is responsible for the typical minty-camphoraceous odor.
    Zusätzliches Material: 4 Tab.
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1992 (1992), S. 1049-1053 
    ISSN: 0170-2041
    Schlagwort(e): Theaspirane analogs ; Spiro ethers ; Geranate, ethyl ; Structure-odor correlation ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Alkylation of ethyl geranate (5) with the bromo esters 7 and 8 gave the β,γ-unsaturated esters 10 and 11, which could be isomerized to 13 and 14 by treatment with DBU. The α,β-unsaturated esters 12-14 were cyclized to 15-17, and subsequent reduction of 15-17 led to the diols 18-20. Final cyclization afforded the spiro ethers 2-4. - The olfactive properties (intensity and quality) of the theaspirane analogs 1-4 are determined by the conformational flexibility of the respective molecule. Thus, the rigid 1 and 2 have strong camphoraceous odors. Augmenting flexibility (→3, →4) results in weaker, fruity-woody notes.
    Zusätzliches Material: 3 Tab.
    Materialart: Digitale Medien
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