- SYNTHESIS OF ALIPHATIC ALCOHOLS AS AROMA CHEMICALS
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The present invention relates to a method for preparing a compound of formula (I). The present invention also relates to compounds of formula (A) or a compound in the form of a stereoisomer. The present invention further relates to the use of a compound of formula (A) as aroma chemical.
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Page/Page column 17
(2019/05/02)
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- Synthesis and catalytic properties of macroporous SiO2-coated CNT-sieve-composite-supported 12-tungstophosphoric acid catalysts with dual pore structure for the Baeyer–Villiger oxidation of cyclic ketones under microwave irradiation
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Carbon nanotube sieves (CNTs-S) with a flutelike shape were synthesized by cutting and perforating using a chemical oxidation etching method. Using the obtained CNTs-S as a hard template, SiO2-coated CNTs-S dual pore structures (CNTs-S@SiO2) were formed. Finally, tungstophosphoric acid was supported on CNTs, CNTs-S, and CNTs-S@SiO2 matrices by the incipient wetness method to obtain the corresponding supported catalysts PW12/CNTs, PW12/CNTs-S, and PW12/CNTs-S@SiO2. The results showed that obtained 30%PW12/CNTs-S and 30%PW12/CNTs-S@SiO2 catalysts in 30 wt% dipping solution had the best catalytic performance for Baeyer–Villiger oxidation of cyclic ketones by H2O2. The conversion of cyclohexanone was 94% and 91%, respectively, in 5 min under microwave irradiation. Cyclopentanone and adamantanone approached quantitative conversion and the selectivity of corresponding lactones reached 100%. The dual pore structure catalyst showed very excellent cyclic stability.
- Wei, Yuli,Yang, Zhiwang,Zhao, Guohu,Yang, Wu
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p. 196 - 206
(2019/02/19)
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- Preparation and Catalytic Property of Multi-walled Carbon Nanotubes Supported Keggin-Typed Tungstosilicic Acid for the Baeyer-Villiger Oxidation of Ketones
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Multi-walled carbon nanotubes (MWCNTs) supported HSiW/MWCNTs was successfully prepared and characterized by Fourier transform infrared spectoscopy, X-ray powder diffraction, transmission electron microscopy and N2 adsorption-desorption test. Its catalytic performance for the catalytic Baeyer-Villiger oxidation of cyclic ketones with 30 % H2O2 as oxidants was investigated. It was found that HSiW/MWCNTs was very efficient to transform of some cycloketones to the corresponding lactones with high conversions as well as selectivities. Factors affecting the oxidations and the reusability of the catalyst were also investigated. It was found that the catalyst can be reused seven times in the catalytic oxidation reaction of cyclopentanone without obviously catalytic activity losing in the oxidation. Graphical Abstract: A supported solid acid of HSiW/MWCNTs was used as efficient catalyst for the Baeyer-Villiger oxidation of ketones. High cyclopentanone conversion (98 %) and ε- valerolactone selectivity (99 %) were obtained. The catalyst can be reused at least seven runs in the oxidation of cyclopentanone.
- Yang, Zhiwang,Xu, Xueqing,Li, Tianjing,Zhang, Nana,Zhao, Xia,Chen, Wenlong,Liang, Xixi,He, Xinli,Ma, Hengchang
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p. 1955 - 1960
(2015/12/24)
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- Lactones 34 [1]. Application of alcohol dehydrogenase from horse liver (HLADH) in enantioselective synthesis of δ- and ε-lactones
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The ability of horse liver alcohol dehydrogenase (HLADH) to the enantioselective oxidation of primary-primary, primary-secondary and primary-tertiary aliphatic 1,5- and 1,6-diols 1a-i was studied. No enantioselectivity of the transformations of primary-primary 1,6-diols 1a-d to ε-lactones 4a-d was observed. Regioselective oxidation of primary-secondary 1,6-diols 1e,f and 1,5-diols 1h,i afforded enantiomerically enriched ε-lactones 4e,f and δ-lactones 4h,i. ε-Lactones 4e,f were formed with higher enantiomeric excesses (e.e. = 85-99%). Enzymatic oxidation of primary-tertiary 1,6-diol 1g did not give lactone product.
- Boratynski, Filip,Kielbowicz, Grzegorz,Wawrzenczyk, Czeslaw
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experimental part
p. 30 - 36
(2010/12/18)
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- NOVEL CYCLIC OXYGENATED COMPOUNDS HAVING COOLING, FRAGRANCE, AND FLAVOR PROPERTIES, AND USES THEREOF
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Compositions that include compounds capable of producing a cooling sensory effect such as certain hydroxy-ketones and hydroxy-aldehyde compounds, their cyclic semi-ketals and semiacetals, and other derivatives thereof. The compounds impart a refreshing and cooling sensation of long duration and high potency, and thus are useful in a variety of formulations, including consumer products such as mouth formulations, food and beverage products, tobacco and smoking articles, fragrances, toiletries, oinments, and the like.
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Page/Page column 23
(2008/06/13)
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- DBU-Catalyzed Deconjugation of 7-Substituted 3,4-Didehydro-2-oxepanones. Deuterium Incorporation, Significance of the Imine Double Bond, and Application to the Synthesis of a Key Pharmacophore
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7-Substituted 3,4-Didehydro-2-oxepanones are conveniently deconjugated to the 4,5-didehydro derivatives by DBU. The isomerization of 7-benzyl-substituted 2-oxepanones proceeds to the extent of 90% over the initial 3 h; the concentration falls gradually thereafter to achieve, in 25 h, a 3:2 equilibrium in favor of deconjugation. Such an equilibrium does not exist for the 7-methyl and the 7-(2-phenethyl) derivatives. The significance of the imine double bond in DBU has been explored. The isomerization in CDCl3 causes deuterium incorporation at positions 3 and 5 of the 2-oxepanones examined and at position 6 of DBU. The mechanistic rationales for these deuterium incorporations are advanced. The transformation of 7-benzyl-3,4-didehydro-2-oxepanone into a bicyclo[3.3.0] skeleton that is present in a diverse class of biologically active natural products is described as a possible potential use of the present deconjugation methodology.
- Jeyaraj, Duraiswamy A.,Kapoor, Kamal K.,Yadav, Veejendra K.,Gauniyal, Harsh M.,Parvez, Masood
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p. 287 - 294
(2007/10/03)
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- The synthesis of menthone by ozonization of menthol
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A selective method of oxidation of menthol to menthone by Co(OAc)2-catalyzed ozonization in ethyl acetate or Freon-113 was developed.
- Odinokov,Botsman,Emel'yanova
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p. 2021 - 2022
(2007/10/03)
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- Some observations on Baeyer-Villiger oxidation of alicylic ketones with magnesium monoperoxyphthalate in aprotic solvent in the presence of bentonite clay
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Magnesium monoperoxyphthalate oxidation of unsubstituted and substituted cyclohexanones has been carried out in acetonitrile in the presence of bentonite clay, affording the corresponding ε-caprolactones in fairly good yields.
- Hirano,Ueno,Morimoto
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p. 3765 - 3775
(2007/10/03)
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- Baeyer-Villiger Oxidation of Ketones Using Molecular Oxygen and Benzaldehyde in the Absence of Metal Catalysts
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A combination system of molecular oxygen, benzaldehyde, and carbon tetrachloride oxidizes various ketones to give lactones and esters in high yields at 40 deg C, and addition of benzoyl chloride increases yields of the Baeyer-Villiger oxidation products at a lower temperature of 20 deg C.
- Kaneda, Kiyotomi,Ueno, Shinji,Imanaka, Toshinobu,Shimotsuma, Emi,Nishiyama, Yutaka,Ishii, Yasutaka
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p. 2915 - 2917
(2007/10/02)
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- Dioxiranes. 20. Preparation and properties of some new dioxiranes
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The in situ method for producing dioxiranes has been modified to permit the isolation in ketone solution of some nonvolatile dioxiranes. The dioxiranes have been characterized spectroscopically and, in some cases, by chemical reactions.
- Murray, Robert W.,Singh, Megh,Jeyaraman, Ramasubbu
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p. 1346 - 1351
(2007/10/02)
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- Stereoselective syntheses of isomers of 3,7-dimethylnonadecane, a sex pheromone of the alfalfa blotch leafminer (Agromyza frontella (Rondani))
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Two related stereoselective syntheses of 3,7-dimethylnonadecane, a sex pheromone of the alfalfa leafminer, are described to show that pulegone can serve as a useful starting material for the preparation of chiral aliphatic isoprenoid compounds.The schemes are designed to place the stereogenic center of pulegone at C.3 in one synthesis and at C.7 in the other so that the optical properties of the products can be compared with one another and with the values calculated using Brewster's rules. Key Words: chiral hydrocarbons, stereoselective synthesis, pheromone, Agromyza frontella.
- Miller, David,Bilodeau, Francois,Burnell, Robert H.
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p. 1100 - 1106
(2007/10/02)
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- Structure-Odor Relationships in Monoterpenolactones
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Twelve γ-, δ- and ε-monoterpenelactones were synthesized, with seven compounds (5, 6, 7, 8, 13, 13', and 15) being newly formed.The odor of the monoterpenolactones was found to be dependent on the size of their rings and their conformation.Substitution of the equatorial methyl group at C(3) in the δ- and ε-monoterpenolactones with a planar molecular shape was necessary for the monoterpenolactones to produce a pronounced maple-like odor.
- Tateba, Hideki,Mihara, Satoru
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p. 2271 - 2276
(2007/10/02)
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- An Oxidative Ether Cleavage with p-Nitroperbenzoic Acid
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The reaction of p-nitroperbenzoic acid in chloroform with alkyl ethers (1a, 2a) leads by selective attack at C - H bonds in α-position to the ether oxygen to hemiacetals, which decompose to aldehydes and alcohols, yielding carboxylic acids.Secondary alkoxy groups as in 3a, 4a furnish Baeyer-Villiger oxidation products of initially formed ketones. Kinetic measurements with substituted benzyl methyl ethers show a Hammett reaction constant ρ = -0.9, which is in accordance with the observed relatively small discrimination between secondary and tertiary C - H bonds.The results are compared with similar hydroxylations of alkanes and with monooxygenase reactions and point to oxenoid transition states.Radical reactions as found with some alkanes are not observed, which is shown by the small amounts of nitrobenzene ( 10percent) formed during the reaction. 13C-NMR shifts of several ethers and oxidation products are reported.
- Schneider, Hans-Joerg,Ahlhelm, Alfred,Mueller, Walter
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p. 3297 - 3302
(2007/10/02)
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