• Title/Summary/Keyword: Ketones.

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The Use of Sodium Chlorate/Hydrochloric Acid Mixtures as a Novel and Selective Chlorination Agent

  • Moon, Byung-Seok;Choi, Han-Young;Koh, Hun-Yeong;Chi, Dae-Yoon
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.472-476
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    • 2011
  • Sodium chlorate/hydrochloric acid mixtures were used to chlorinate activated arenes and the $\alpha$-position of ketones. This chlorination method was used to produce selectively mono-, di-, and trichlorinated compounds by controlling the molarity of sodium chlorate. This reagent proved to be much more efficient and easier to handle than chlorine gas.

Efficient Synthesis of β-Acetamido Ketones by Silver(I) Triflate-Catalyzed Multicomponent Reactions

  • Pandit, Rameshwar Prasad;Lee, Yong Rok
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3559-3564
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    • 2012
  • An efficient one-pot synthesis of ${\beta}$-acetamido ketones was accomplished by AgOTf-catalyzed multicomponent reactions of substituted acetophenones with aromatic aldehydes and acid chloride in acetonitrile in high yields. The methods offer several significant advantages of easy handling, mild reaction conditions, and use of effective and non-toxic catalyst.

Volatile Compounds in Oyster Hydrolysate Produced by Commercial Protease

  • Cha, Yong-Jun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.24 no.3
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    • pp.420-426
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    • 1995
  • Volatile compounds in raw oyster and oyster hydrolysate produced with protease were compared by vacuum simultaneous steam distillation-solvent extraction/gas chromatography/mass spectrometry. Sixty-two volatile compounds were detected in both samples. Of these, 57 were positively identified, composed mainly of aldehydes(12), ketones(9), alcohols(14), nitrogen-containing compounds(9), acids(6), terpenes(4), and miscellneous compounds(8). Levels of acids decreased after hydrolysis, whereas several other compounds such as aldehydes, ketones, and nitrogen containing compounds increased. Pyrazines, found in high abundance, were only detected in oyster hydrolysate.

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MO Theoretical Studies on Diels-Alder Reactions of $\alpha$-Allenic Ketones$^*$

  • Han, Eun-Sook;Lee, Ik-choon;Chang Byung-Doo
    • Bulletin of the Korean Chemical Society
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    • v.4 no.5
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    • pp.197-200
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    • 1983
  • The Diels-Alder cycloaddition reactions between dienes and allenic ketones were studied theoretically using CNDO/2 method. It was found that the reaction is a neutral electron demand type with matrix element control and the reactivity, the regio- and stereo-selectivities can be correctly predicted based on interaction energies calculated with the 4-center FMO formalism.

Halogenation of Aldehydes and Ketones by Selenium (IV) Oxyhalides Generated in-situ from Selenium Dioxide and Halotrimethylsilanes

  • 이종근;박인수;서종화
    • Bulletin of the Korean Chemical Society
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    • v.16 no.4
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    • pp.349-355
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    • 1995
  • Bromo-and chlorotrimethylsilane react with selenium dioxide in halocarbon solvents and generate selenium oxybromide and oxychloride, respectively. These in-situ generated oxyhalides turned out to be very efficient for selective bromination and chlorination of aldehydes and ketones. Under carefully controlled reaction conditions, second and third introduction of halogens into carbonyl compounds can be greatly suppressed, and high yields of monohalo compounds were obtained. The product ratios of this halogenation reactions can be best explained if the reactions are assumed to involve intermediate β-ketoselenenyl chlorides.

Analysis of Volatile Flavor Components from Allium senescens (두메부추의 휘발성 향기성분 분석)

  • 이미순;정미숙
    • Korean journal of food and cookery science
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    • v.17 no.1
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    • pp.55-59
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    • 2001
  • To investigate the usefulness of Allium senescens as a aromatic edible plant, volatile flavor components and flavor pattern were analyzed. Essential oils of fresh and freeze dried Allium senescens were extracted by SDE(simultaneous steam distillation and extraction) method using diethyl ether as solvent. And their volatile flavor components were analyzed by gas chromatography(GC) and gas chromatography-mass spectrometry (GC-MS). A total of 46 components, including 11 hydrocarbons, 9 aldehydes, 4 alcohols, 2 esters, 7 acids, 4 ketones and 9 sulfur containing compounds were identified in fresh Allium senescens. In freeze dried Allium senescens, 8 hydrocarbons, 5 aldehydes, 3 alcohols, 5 esters, 2 acids, 3 ketones and 4 sulfur containing compounds were identified. Volatile flavor patterns of Chinese chive and Allium senescens were compared using electronic nose. The score of first principal component was significantly different in Allium senescens and Chinese chive.

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Palladium Catalyzed New Synthesis of Divinyl Ketones and Divinyl ${\alpha}$-Diketones (팔라듐 촉매를 이용한 디비닐케톤과 디비닐 ${\alpha}$-디케톤의 새로운 합성)

  • Jin Il Kim;Kwang Hyek Lee;Seung Jae Im
    • Journal of the Korean Chemical Society
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    • v.33 no.5
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    • pp.522-529
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    • 1989
  • Symmetrical divinyl ketones and divinyl ${\alpha}$-diketones were synthesized in moderately good yields through palladium catalyzed carbonylative homocoupling reaction of vinylic halides. Divinyl ${\alpha}$-diketones were obtained in the highest yield in the presence of 10 atm of carbon monoxide, using 2 mol% ligand added to palladium(II) acetate as catalyst and three equivalents of tributylamine as base in polar solvent at $100^{\circ}C$. Divinyl ketones were synthesized mainly under atmospheric pressure of carbon monoxide. The reaction was also proceeded to several other vinylic halides under the above reaction condition. Thus, divinyl ketones and divinyl ${\alpha}$-diketones were synthesized selectively as expected.

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Resolution of Aryl α-Aminoalkyl Ketones on a Doubly Tethered Liquid Chromatographic Chiral Stationary Phase Based on (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic Acid

  • Jin, Kab-Bong;Kim, Hee-Jin;Hyun, Myung-Ho
    • Journal of the Korean Chemical Society
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    • v.55 no.5
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    • pp.751-755
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    • 2011
  • A doubly tethered chiral stationary phase (CSP) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was applied to the resolution of various aryl ${\alpha}$-aminoalkyl ketones with the use of 80% ethanol in water containing 10 mM sulfuric acid as a mobile phase. The chiral resolution was quite successful, the separation factors (${\alpha}$) and the resolutions ($R_S$) being in the range of 1.39-2.05 and 3.18-5.22, respectively. The separation factors (${\alpha}$) on the doubly tethered CSP were slightly worse than those on the corresponding singly tethered CSP. However, the resolutions ($R_S$) on the doubly tethered CSP were generally greater than those on the corresponding singly tethered CSP. The chromatographic behaviors for the resolution of aryl ${\alpha}$-aminoalkyl ketones on the doubly tethered CSP were demonstrated to be dependent on the type and the content of the organic and acidic modifiers in aqueous mobile phase and the column temperature.

Synthesis and Biological Evaluation of Tetrapeptide Ketones as Reversible 20S Proteasome Inhibitors

  • Latif, Muhammad;Jung, Myoung Eun;Lee, Kwangho;Choi, Gildon
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3571-3575
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    • 2014
  • Proteasome, a multicatalytic protease complex, has been validated as a promising therapeutic target in oncology. Carfilzomib (Kyprolis$^{(R)}$), a tetrapeptide epoxyketone, irreversibly inhibits the chymotrypsin-like (CT-L) activity of the proteasome and has been recently approved for multiple myeloma treatment by FDA. A chemistry effort was initiated to discover the compounds that are reversibly inhibit the proteasome by replacing the epoxyketone moiety of carfilzomib with a variety of ketones as reversible and covalent warheads at the C-terminus. The newly synthesized compounds exhibited significant inhibitory activity against CT-L activity of the human 20S proteasome. When the compounds were tested for cancer cell viability, 14-8 was found to be most potent in inhibiting Molt-4 acute lymphoblastic leukemia cell line with a $GI_{50}$ of $4.4{\mu}M$. Cytotoxic effects of 14-8 were further evaluated by cell cycle analysis and Western blotting, demonstrating activation of apoptotic pathways.