- Converting S-limonene synthase to pinene or phellandrene synthases reveals the plasticity of the active site
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S-limonene synthase is a model monoterpene synthase that cyclizes geranyl pyrophosphate (GPP) to form S-limonene. It is a relatively specific enzyme as the majority of its products are composed of limonene. In this study, we converted it to pinene or phellandrene synthases after introducing N345A/L423A/S454A or N345I mutations. Further studies on N345 suggest the polarity of this residue plays a critical role in limonene production by stabilizing the terpinyl cation intermediate. If it is mutated to a non-polar residue, further cyclization or hydride shifts occurs so the carbocation migrates towards the pyrophosphate, leading to the production of pinene or phellandrene. On the other hand, mutant enzymes that still possess a polar residue at this position produce limonene as the major product. N345 is not the only polar residue that may stabilize the terpinyl cation because it is not strictly conserved among limonene synthases across species and there are also several other polar residues in this area. These residues could form a “polar pocket” that may collectively play this stabilizing role. Our study provides important insights into the catalytic mechanism of limonene synthases. Furthermore, it also has wider implications on the evolution of terpene synthases.
- Xu, Jinkun,Ai, Ying,Wang, Jianhui,Xu, Jingwei,Zhang, Yongkang,Yang, Dong
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- Imidazo[1,2-a]pyridine-ylmethyl-derivatives and their use as flavoring agents
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The present invention primarily relates to imidazo[1,2-a]pyridine-ylmethyl-derivatives of Formula (I) wherein R1, R2, X, W e J are as defined in the description, to mixtures thereof and to the use thereof as flavoring agents. The compounds in accordance with the present invention are suitable for producing, imparting, or intensifying an umami flavor. The invention further relates to flavoring mixtures, compositions for oral consumption as well as ready-to-eat, ready-to-use and semifinished products, comprising an effective amount of the compound of Formula (I) and to specific methods for producing, imparting, modifying and/or intensifying specific flavor impressions.
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- Effect of high-temperature calcination on the generation of Bronsted acid sites on WO3/Al2O3
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The acid properties of a series of alumina-supported tungsten oxide (WO3/Al2O3) catalysts with loadings of 5-50 wt% WO3 calcined at various temperatures were investigated by acid-catalyzed reactions (benzylation of anisole and isomerization of α-pinene) and FTIR spectroscopy. The relationships between acid properties, structures, and catalytic performances were evaluated. Both the catalytic activity and amount of Bronsted acid sites depend on the calcination temperature and WO3 loading. High-temperature calcination (1123 K) generated Bronsted acid properties, and 20 wt% WO 3/Al2O3 calcined at 1123 K exhibited the highest activity among the catalysts tested. The activities for the benzylation of anisole and α-pinene isomerization over WO3/Al 2O3 calcined at 1123 K were proportional to the Bronsted acidity, which indicates that these reactions occurred on the Bronsted acid sites. Tungsten oxide, which has distorted octahedral symmetry, was loaded as 2D monolayer domains below 20 wt%, and these domains covered most of the alumina surface at 20 wt%. If the WO3 loading was sufficient to form 2D tungsten oxide monolayer sheets (>20 wt%), some of the Bronsted acid sites on WO3/Al2O3 were obscured by monoclinic WO3 that has no Bronsted acid sites, which resulted in a decrease of the catalytic activity. This suggests that Bronsted acid sites are generated at the boundaries between tungsten oxide monolayer domains.
- Kitano, Tomoyuki,Hayashi, Tomohiro,Uesaka, Toshio,Shishido, Tetsuya,Teramura, Kentaro,Tanaka, Tsunehiro
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p. 2011 - 2020
(2014/08/05)
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- Unique catalysis of gold nanoparticles in the chemoselective hydrogenolysis with H2: Cooperative effect between small gold nanoparticles and a basic support
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Gold nanoparticles on hydrotalcite act as a heterogeneous catalyst for the chemoselective hydrogenolysis of various allylic carbonates to the corresponding terminal alkenes using H2 as a clean reductant. The combination of gold nanoparticles and basic supports elicited significantly unique and selective catalysis in the hydrogenolysis.
- Noujima, Akifumi,Mitsudome, Takato,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
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p. 6723 - 6725
(2012/07/28)
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- Catalytic activity of the VIII group metals in the hydrogenation and isomerization of α- And β-pinenes
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The kinetic regularities of the liquid-phase hydrogenation and isomerization of α- and β-pinenes over the Pd/C, Ru/C, Rh/C, Pt/C, and Ir/C catalysts were studied at temperatures ranging from 20 to 100 °C and at hydrogen pressures of 1-11 bar using n-octane as the solvent. The hydrogenation and isomerization of α- and β-pinenes occur simultaneously on the Ru/C, Rh/C, Pt/C, and Ir/C catalysts, and the reaction mixture contains the products of double bond hydrogenation, viz., cis- and trans-pinanes. The Ru, Rh, and Pd metals have a higher catalytic activity in β-pinene isomerization than Ir and Pt. Among the VIII Group metals studied, the Pd-based catalyst has the highest catalytic activity in double bond isomerization of α- and β-pinenes. The general scheme of the mechanism of hydrogenation and isomerization of α- and β-pinenes on the Pd/C catalyst was proposed.
- Deliy,Simakova
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body text
p. 2056 - 2064
(2010/05/02)
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- Biochemistry and molecular genetics of the biosynthesis of the earthy odorant methylisoborneol in Streptomyces coelicolor
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Methylisoborneol (2) is a volatile organic compound produced by a wide variety of Actinomycete soil organisms, myxobacteria, and cyanobacteria. It has an unusually low odor threshold and, together with geosmin, is responsible for the characteristic smell of moist soil as well as unpleasant taste and odor episodes associated with public water supplies and contamination of various foodstuffs, including fish, wine, and beer. Despite considerable interest in detection and remediation of methylisoborneol, the biosynthesis of this methylated monoterpene has been obscure. In Streptomyces coelicolor, the sco7700 and sco7701 genes are shown to correspond to a two-gene operon responsible for methylisoborneol biosynthesis. Both genes have been amplified by PCR and the resulting DNA has been cloned and expressed in Escherichia coli. Incubation of recombinant SCO7701 protein, annotated as a possible C-methyltransferase, with geranyl diphosphate (1) and S-adenosylmethionine gave the previously unknown compound, (E)-2-methylgeranyl diphosphate (3). Incubation of 3 in the presence of Mg2+ with recombinant SCO7700, previously annotated only as a possible metal-binding protein or terpenoid synthase, resulted in the formation of 2-methylisoborneol (2). The steady-state kinetic parameters for both biochemical reactions have been determined. Incubation of geranyl diphosphate and S-adenosylmethionine with a mixture of both SCO7700 and SCO7701 resulted in formation of methylisoborneol (2). Cyclization of 2-methylgeranyl diphosphate (3) to methylisoborneol (2) likely involves the intermediacy of 2-methyllinalyl diphosphate. Copyright
- Wang, Chieh-Mei,Cane, David E.
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supporting information; experimental part
p. 8908 - 8909
(2009/02/03)
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- Isomerization of α-pinene over dealuminated ferrierite-type zeolites
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Isomerization of α-pinene was performed on a series of dealuminated ferrierite (FER)-type zeolites in liquid phase at 363 K using a batch reactor. The course of zeolite dealumination was followed in detail using 29Si, 27Al, 1H MAS NMR, XRD, FTIR, and sorption of nitrogen. The ammonium form of FER was dealuminated with aqueous solutions of HCl. While retaining the crystallinity of the zeolite particles, the treatments removed up to 53% of the tetrahedrally coordinated aluminum atoms from the FER framework. According to 29Si MAS NMR studies, the framework aluminum atoms located at the 10-membered rings in the main channels of FER (TB sites) were depleted preferentially from their positions. Even relatively mild dealumination of FER led to an active catalyst containing both Bronsted and Lewis centers, yielding up to 97% conversion of α-pinene at 363 K, in contrast to the 72% observed for the parent hydrogen form. Such catalytic behavior was discussed in terms of the conversion of a reactant inside micropores of the zeolite catalyst, on Bronsted acid centers with enhanced strength located probably in the vicinity of Lewis sites. The selectivity toward camphene and limonene changed smoothly with the dealumination level; thus, a higher selectivity toward limonene was observed at the expense of camphene formation with increasing the nSi / nAl ratio of the catalysts. The selectivity toward camphene and limonene was close to 85% for all of the materials studied. The initial rates of α-pinene transformations over FER-type materials exceeded those observed for other catalytic systems, heteropoly acid/SiO2 and H2SO4/ZrO2. This study demonstrates the successful application of a medium-pore zeolite for the catalytic transformation of α-pinene in liquid phase.
- Rachwalik, Rafal,Olejniczak, Zbigniew,Jiao, Jian,Huang, Jun,Hunger, Michael,Sulikowski, Bogdan
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p. 161 - 170
(2008/09/17)
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- Efficient triplet-triplet energy transfer using clay-bound ionic sensitizers
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Both cationic and anionic clays, with sensitizers anchored onto their interlayer by ionic linkage, are found to be useful 'microreactors' to achieve triplet state reactivity of myrcene in an experimentally simple, inexpensive and clean reaction. These clay-bound sensitizers are characterized by X-ray and their advantages are highlighted.
- Madhavan,Pitchumani
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p. 9041 - 9044
(2007/10/03)
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- A cDNA clone for β-caryophyllene synthase from Artemisia annua
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An homology-based cloning strategy yielded a full-length cDNA from Artemisia annua that encoded a protein of 60.3 kDa which resembled a sesquiterpene synthase in sequence. Heterologous expression of the gene in Escherichia coli provided a soluble recombinant enzyme capable of catalyzing the divalent metal ion-dependent conversion of farnesyl diphosphate to β-caryophyllene, a sesquiterpene olefin found in the essential oil of A. annua. In reaction parameters and kinetic properties, β-caryophyllene synthase resembles other sesquiterpene synthases of angiosperms. The β-caryophyllene synthase gene is expressed in most plant tissues during early development, and is induced in mature tissue in response to fungal elicitor thus suggesting a role for β-caryophyllene in plant defense.
- Cai, Yu,Jia, Jun-Wei,Crock, John,Lin, Zhi-Xin,Chen, Xiao-Ya,Croteau, Rodney
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p. 523 - 529
(2007/10/03)
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- Monoterpene synthase activities in leaves of Picea abies (L.) Karst. and Quercus ilex L.
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In addition to direct ecological functions in the interaction of plants with the environment, the emission of monoterpenes, especially from the foliage of evergreen trees, is of great importance for the production of ozone and photochemical oxidants in the troposphere. In the present work, we established a reproducible non-radioactive standard enzyme assay and characterized monoterpene synthase activities in needles of Norway spruce (Picea abies (L.) Karst.) and in leaves of holm oak (Quercus ilex L.). In Norway spruce, the dominant monoterpenes formed were α-pinene, camphene, and to a lesser extent β-pinene and limonene. In holm oak, α-pinene, sabinene, and β-pinene were the main products, while limonene was a minor component. Under optimum conditions, in both Norway spruce and holm oak, monoterpene formation remained constant up to 180 min and 90 min, respectively, and varied with the buffer and Mg2+ and Mn2+ concentrations used. Optimum temperature for monoterpene synthase activity was 40°C in both species; optimal pH ranged between 6.5 and 7.5 in both species. Apparent Michaelis- constants for the substrate GDP were ca. 17.9 ± 5.1 μM for Norway spruce and ca. 69.4 ± 22.1 μM for holm oak. Molecular weight determination by FPLC indicated that the monoterpene synthases in Norway spruce and holm oak have native molecular weights of ca. 59 and 50 kDa, respectively. (C) 2000 Elsevier Science Ltd.
- Fischbach, Robert J.,Zimmer, Ina,Steinbrecher, Rainer,Pfichner, Andreas,Schnitzler, Joerg-Peter
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p. 257 - 265
(2007/10/03)
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- Fine particle and gaseous emission rates from residential wood combustion
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Residential wood combustion emissions were analyzed to determine emission rates and to develop chemical emissions profiles that represent the appliances and woods typically used in wood-burning-communities. Over 350 elements, inorganic compounds, and organic compounds were quantified. A range of 4-9 g/kg dry fuel of particulate matter(a dilution stack sampler equipped with a 2.5-μm particle selective cyclone. Emissions were diluted 20-70 times, cooled to ambient temperature, and allowed 80 s for condensation prior to collection. Wood type, wood moisture, burn rate, and fuel load were varied for different experiments. Fine particle and se mivolatile organic compounds were collected on filter/PUF/XAD/PUF cartridges. Inorganic samples and mass were collected on Teflon and quartz filters. Volatile organic carbon compounds were trapped with Tenax (C8- C20), canister (C2-C12), and 2,4-dinitrophenylhydrazine impregnated cartridges (carbonyl compounds). Analysis of particle and semivolatile organic species was conducted by gas chromatography/mass spectrometry. Teflon filters were analyzed for mass by gravimetry, trace elements were analyzed by X-ray fluorescence and ammonium was analyzed by automated colorimetry. Quartz filters were analyzed for organic and elemental carbon by thermal/optical reflectance, and forts were analyzed by ion chromatography. Select quartz filters were analyzed by accelerator mass spectrometry for carbon-12 and carbon-14 abundance. Canister and Tenax samples were analyzed by gas chromatography with a flame ionization detector, and carbonyl compounds were analyzed by high-performance liquid chromatography. Residential wood combustion emissions were analyzed to determine emission rates and to develop chemical emissions profiles that represent the appliances and woods typically used in wood-burning communities. Over 350 elements, inorganic compounds, and organic compounds were quantified. A range of 4-9 g/kg dry fuel of particulate matter (a dilution stack sampler equipped with a 2.5-μm particle selective cyclone. Emissions were diluted 20-70 times, cooled to ambient temperature, and allowed 80 s for condensation prior to collection. Wood type, wood moisture, burn rate, and fuel load were varied for different experiments. Fine particle and semivolatile organic compounds were collected on filter/PUF/XAD/PUF cartridges. Inorganic samples and mass were collected on Teflon and quartz filters. Volatile organic carbon compounds were trapped with Tenax (C8-C20), canister (C2-C12), and 2,4-dinitrophenylhydrazine impregnated cartridges (carbonyl compounds). Analysis of particle and semivolatile organic species was conducted by gas chromatography/mass spectrometry. Teflon filters were analyzed for mass by gravimetry, trace elements were analyzed by X-ray fluorescence, and ammonium was analyzed by automated colorimetry. Quartz filters were analyzed for organic and elemental carbon by thermal/optical reflectance, and ions were analyzed by ion chromatography. Select quartz filters were analyzed by accelerator mass spectrometry for carbon-12 and carbon-14 abundance. Canister and Tenax samples were analyzed by gas chromatography with a flame ionization detector, and carbonyl compounds were analyzed by high-performance liquid chromatography.
- Mcdonald, Jacob D.,Zielinska, Barbara,Fujita, Eric M.,Sagebiel, John C.,Chow, Judith C.,Watson, John G.
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p. 2080 - 2091
(2007/10/03)
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- HAPs release from wood drying
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Hazardous Air Pollutant (HAP) profiles from drying softwood and hardwood flakes (for the manufacture of oriented strand board) are very similar, indicating that they originate through a common mechanism, the breakdown of wood tissue. Hence, the strategies employed to reduce VOC (volatile organic compound) emissions from hardwood can also be extended to decreasing HAPs from softwood. Drying aspen flakes in the field and in the laboratory gives rise to different VOC species, and direct extension of laboratory data to the field may prove difficult. Formaldehyde emissions from drying fresh aspen flakes are lower than those from stored material; the opposite effect occurs for methanol and the other aldehydes. HAPs evolved from drying pine flakes surge sharply at 5-10% moisture content during drying at 130-160 °C. Emissions of methanol, formaldehyde, pentanal, and hexanal all begin simultaneously, with the release of methanol and formaldehyde being the most sensitive to dryer temperature. Hence, the nature of the VOC mix is partly governed by the dryer temperature. Pine and aspen give rise to similar HAPs profiles during either drying or pressing flakes that are already dried.
- Otwell, Lawrence P.,Hittmeier, Michael E.,Hooda, Usha,Yan, Hui,Su, Wei,Banerjee, Sujit
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p. 2280 - 2283
(2007/10/03)
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- Generation of acid sites on silica-supported rare earth oxide catalysts: Structural characterization and catalysis for α-pinene isomerization
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Silica-supported rare earth oxide catalysts (Ln/SiO2; Ln = La, Ce, Pr, Sm, Eu, Tb, Yb and Y), loading amounts of which were 3.4 mmol g (support)- 1, were characterized by α-pinene isomerization, temperature-programmed desorption (TPD), Fourier transform infrared (FTIR), X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), thermogravimetric-differential thermal analysis (TG-DTA) and Raman spectroscopy. In the lanthanoid series, the catalytic activity increased with atomic number from 57La to 70Yb, except for Ce. All the Ln/SiO2 catalysts, except for Ce, were amorphous. On the surface of the catalyst, Ln-O-Si and Ln-O-Ln linkages formed, the ratio of which varied with the loaded element. The ratio of Ln-O-Si linkage increases with stronger affinity among LnO(n) units and SiO4 tetrahedra, and the affinity depends on the size of Ln3+. With increasing ratio of Ln-O-Si to Ln-O-Ln linkage, the catalytic activity increases. Silica-supported yttrium oxide catalyst, the trivalent ion radius of which is quite similar to that of ytterbium, exhibited the same activity as that of Yb/SiO2. Raman spectroscopic characterization revealed that excess loading of Yb atoms on SiO2-support block Yb-O-Si linkage to form Yb2O3 fine particles. When Yb/SiO2 was pretreated at 1273 K, fine ytterbium silicate crystallites formed. Ln-O-Si linkage without a long-ranged ordering structure was the active site for α-pinene isomerization.
- Yamamoto, Takashi,Matsuyama, Takahiro,Tanaka, Tsunehiro,Funabiki, Takuzo,Yoshida, Satohiro
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p. 2841 - 2849
(2007/10/03)
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- Chemoselective removal of allylic formyloxy group using SmI2
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A variety of allylic formates are chemoselectively transformed into th corresponding olefins in excellent yields on treatment with SmI2 in THF-HMPA-H2O (20:5:1), even though allylic acetate and allylic ether groups are present in the same molecule.
- Shibuya,Shiratsuchi
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p. 431 - 449
(2007/10/02)
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Reaction of alkyl hydroperoxides (1(ary), 2(ary) or 3(ary)) upon tertiary alkyl trichloroacetimidates under acidic catalysis yielded unsymmetrical dialkyl peroxides with yields in the range 30-70%.
- Bourgeois,Montaudon,Maillard
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p. 2477 - 2484
(2007/10/02)
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- Preparation and Some Reactions of Allylic Indium Reagents
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A variety of allylic indium sesquihalides were readily prepared by the reaction of indium powder with allylic halides in DMF at room temperature.Protonation of the allylindium reagents proceeded regiospecifically at the γ-position of the allylic group to give 1-propenes.A facile transformation of α-pinene to β-pinene was achieved via a myrtenylindium intermediate.Oxygenation of the allylic indium reagents gave mixtures of allylic alcohol isomers in moderate yields.The coupling of the allylindium reagents with cyclic imides gave diverse products depending on the structures of the substrates and the reagents.Stannylation with tributylchlorostannane occurred exclusively at the α-carbon, yielding allyltributylstannanes; E,Z isomerization of the allylic double bond depended largely upon the substitution pattern on the allylic moiety.
- Araki, Shuki,Shimizu, Toshio,Johar, Perminder S.,Jin, Shun-Ji,Butsugan, Yasuo
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p. 2538 - 2542
(2007/10/02)
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- Synthesis of Terpenes Containing the Bicycloheptane Ring System by the Intramolecular Cycloaddition Reaction of Vinylketenes with Alkenes. Preparation of Chrysanthenone, β-Pinene, β-cis-Bergamotene, β-trans-Bergamotene, β-Copaene, and β-Ylangene and Lemnalol
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Treatment of geranoyl chloride (20) with triethylamine in toluene at reflux gave the vinylketene 21 which underwent a cycloaddition to give 7,7-dimethyl-2-methylenebicycloheptan-6-one (24) in 43percent yield.Isomerization over Pd gave chrysanthenone (6) in quantitative yield.Wolf-Kischner reduction gave β-pinene (5) in 70percent yield.A similar sequence of reactions starting from (Z,E)- and (E,E)-farnesoyl chloride gave ketones 51 and 57, which were converted to β-cis-bergamotene (8) and β-trans-bergamotene (9), respectively. β-Copaene (10) and β-ylangene (11) were prepared from 57 by a three-step sequence.Treatment of the imidazole 59 with tri-n-butyltin hydride in toluene at reflux gave a 46percent yield of a 1:1 mixture of 10 and 11.Selenium dioxide oxidation of 11 gave the antitumor agent lemnalol.The mechanisms of the regiospecific ketene generation and the cycloaddition reaction have been explored, and the reactivity of the novel bicycloheptanones has been examined.
- Kulkarni, Yashwant S.,Niwa, Maho,Ron, Eyal,Snider, Barry B.
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p. 1568 - 1576
(2007/10/02)
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- Intramolecular Cycloadditions of Ketenes. 2. Synthesis of Crysanthenone, β-Pinene, β-cis-Bergamotene, and β-trans-Bergamotene
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Vinylketenes prepared from geranoyl and farnesoyl chloride by treatment with triethylamine react to give bicycloheptanones which can be converted to β-pinene and the β-bergamotenes by Wolff-Kishner reduction.
- Kulkarni, Yashwant S.,Snider, Barry B.
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p. 2809 - 2810
(2007/10/02)
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- A TRICYCLIC TERPENE HYDROCARBON - CYCLOPINENE
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The reduction of the tosylate of filipendulol (2,7,7-trimethylbicyclohept-2-en-6-ol) with lithium tetrahydroaluminate in ether has given a hydrocarbon (I), C10H16 (bp 66.5 deg C/50 mm, n20D 1.4565, d2020 0.8599, 19D -104.5 deg.NMR: 0.69 ppm (CH3); 0.95 ppm, (CH3); 1.17 ppm (CH3); no signals of olefinic protons.IR: 3054 cm-1 (three-membered ring with gem-protons); 1363 and 1387 cm-1 (gem-CH3), absorption bands of multiple bonds absent.Heating (70 deg C) (I) with a sulfonated cation-exchange resin in hexane gave α-pinene.The hydrogenation of (I) over PtO2 in acetic acid gave pinane.The most probable structure of (I) is 2,7,7-trimethyltricyclo2,4>heptane.The substance has been called cyclopinene.
- Dembitskii, A. D.,Yurina, R. A.,Goryaev, M. I.
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p. 671 - 673
(2007/10/02)
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- REACTIONS OF TERPENES IN DIPOLAR APROTIC SOLVENTS. PART III. ISOMERIZATION OF SOME MONOTERPENE HYDROCARBONS
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Acyclic (myrcene, ocimene, alloocimene), monocyclic (limonene) and bicyclic (α-pinene, β-pinene, (+)-3-carene) terpene hydrocarbons heated in dipolar aprotic solvents (DMF, DMSO, TMS) undergo complex conversions where isomerization processes prevail.The isomerization degree of particular hydrocarbons depends both on the structure of initial compound and the type of solvent used.
- Matawowski, Aleksander
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p. 469 - 479
(2007/10/02)
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- Preparation of para-menth-1-ene-7-sulfonate salts and corresponding acids
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Para-menth-1-ene-7-sulfonate salts are made by reacting β-pinene with a bisulfite salt under free radical conditions.
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- Process for separating alpha-pinene from beta-pinene
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A process for effecting at least the partial resolution of a first pinene mixture containing alpha pinene and beta pinene is described comprising the sequential steps of (i) admixing diethylene glycol with said first pinene mixture of alpha pinene and beta pinene thus forming a second pinene mixture; (ii) subjecting the resulting second pinene mixture of alpha pinene, beta pinene and diethylene glycol to fractional azeotropic distillation yielding (A) a distillate which is a two liquid phase non-emulsified composition the first phase of which is the lower phase and which consists essentially of diethylene glycol and the second phase of which is the upper phase and which consists essentially of a third pinene mixture consisting essentially of alpha pinene and beta pinene, substantially richer in alpha pinene than said first pinene mixture and (B) a bottoms mixture, which is a two liquid phase, non-emulsified composition, the first phase of which is the lower phase and which consists essentially of diethylene glycol and the second phase of which is the upper phase and which consists essentially of alpha-pinene and beta-pinene substantially richer in beta-pinene than said first pinene mixture; and (iii) physically separating said first phase from said second phase by means of decantation. A preferred manner of carrying out such process comprises the sequential steps of (i) first removing, in the absence of azeotroping agent, by means of distillation a portion of the α-pinene from the first pinene mixture whereby 80% of the α-pinene is removed from the first pinene mixture of α-pinene and beta pinene and whereby said first pinene mixture is enriched in concentration of beta pinene, thereby forming a second pinene mixture; (ii) admixing diethylene glycol with the resulting second pinene mixture of alpha pinene and beta pinene to form a third pinene mixture; (iii) subjecting the resulting third pinene mixture of alpha pinene, beta pinene and diethylene glycol to fractional azeotropic distillation yielding (A) a distillate which is a two liquid phase non-emulsified composition; the first phase of which is a lower phase and which consists essentially of diethylene glycol and the second phase of which is the upper phase and which consists essentially of a fourth pinene mixture consisting essentially of alpha pinene and beta pinene substantially richer in alpha pinene than said second pinene mixture and (B) a bottoms mixture, which is a two liquid phase, non-emulsified composition, the first phase of which is the lower phase and which consists essentially of diethylene glycol and the second phase of which is the upper phase and which consists essentially of alpha-pinene and beta-pinene substantially richer in beta-pinene than said first pinene mixture; and (iv) physically separating said first phase from said second phase by decantation.
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