• Title/Summary/Keyword: Ketones.

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Solvent Effects upon Carbonyl Stretching Freguency Shifts of Raman Spectra : Ketones (라만 스펙트럼의 카보닐 신축진동 이동에 대한 용매효과 : 케톤)

  • In Ju Lee;Sung Hun Seo;Mu Sang Lee
    • Journal of the Korean Chemical Society
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    • v.37 no.12
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    • pp.987-994
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    • 1993
  • Inductive and resonance effects play an important role in determining carbony) stretching frequencies of ketones. Hydrogen bonding, dielectric effects, and steric effects are all factors which determine the carbonyl stretching frequency, νC=O of ketones in solution. The $ν_{C=O}$ frequencies were shifted by approximately 27$cm^{-1}$ each by substituting to a phenyl group for a methyl group in acetone. The $ν_{C=O}$ frequency for ketones shifted differently in various solvents and increased with increasing the volume ratio of the ketones in water solutions. The $ν_{C=O}$ frequency for ketones shifts continously at constant concentration of ketone in solutions of $(CH_3)_2SO/CCl_4$and$CHCl_3/CCl_4$ with changing of the mole ratio of two solvents. The $ν_{C=O}$ frequency was also affected by changing concentration in either $CCl_4$ or $(CH_3)_2SO$ solution and in either $CCl_4$or $CHCl_3$ solution.

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A Study on Extraction and Adsorption of Three Phenolic Ketones (페놀케톤 3종의 추출 및 흡착에 관한 연구)

  • Sang Cheol Lee
    • Korean Chemical Engineering Research
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    • v.61 no.1
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    • pp.109-115
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    • 2023
  • The extraction and adsorption characteristics for three phenolic ketones with high physicochemical similarity among phenolic compounds, which are alcohol fermentation inhibitors in lignocellulosic biomass hydrolysates, were investigated. The most suitable basic extractant for selectively separating acetosyringone from three phenol ketones by reactive extraction was found to be trioctylphosphine oxide. In addition, it was found that adsorption using XAD16, a polymer neutral resin adsorbent, or physical extraction using hexane, was a suitable separation method for separation of 4'-hydroxyacetophenone (HAP) and acetovanillone (AVO). A five-step fractionation process including extraction and adsorption mentioned above has been first proposed to separate and concentrate the three phenol ketones present at equal mass percentages. When physical extraction with n-hexane and re-extraction with an aqueous NaOH solution were used as the steps 4 and 5 in the fractionation process respectively, it was possible to obtain almost 70% or more of the purity of three phenolic ketones.

Volatile Compounds of Elsholtzia splendens (꽃향유의 휘발성 향기성분)

  • Lee, So-Young;Chung, Mi-Sook;Kim, Mi-Kyung;Baek, Hyung-Hee;Lee, Mi-Soon
    • Korean Journal of Food Science and Technology
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    • v.37 no.3
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    • pp.339-344
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    • 2005
  • Volatile compounds, isolated from Elsholtzia splendens using simultaneous steam distillation extraction (SDE) and headspace solid phase microextraction (HS-SPME), were analyzed by gas chromatography/mass spectrometry(GC-MS). Twenty-nine compounds, comprising 3 aldehydes, 7 alcohols, 11 hydrocarbons, 5 ketones, and 3 miscellaneous ones, were tentatively identified from volatile compounds of Elsholtzia splendens flowers. From leaves, 30 compounds, comprising 3 aldehydes, 6 alcohols, 11 hydrocarbons, 6 ketones, and 11 miscellaneous ones, were tentatively identified. Volatile compounds extracted by HS-SPME in E. splendens flowers were 3 alcohols, 18 hydrocarbons, 3 ketones, and 2 miscellaneous ones. In leaves, 31 compounds, comprising 7 alcohols, 15 hydrocarbons, 7 ketones, and 2 miscellaneous ones, were tentatively identified. Major volatile compounds identified by SDE and HS-SPME were naginataketone and elsholtziaketone, which were identified as aroma-active compounds, representing characteristic aroma of E. splendens.

Selective Reduction of $\alpha,\beta$-Unsaturated Ketones with Borohydride Exchange Resin-$CuSO_4$ in Methanol

  • Yoon, Nung-Min;Sim, Tae-Bo
    • Bulletin of the Korean Chemical Society
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    • v.14 no.6
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    • pp.749-752
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    • 1993
  • Borohydride exchange resin $(BER)-CuSO_4$ system readily reduces {\alpha},{\beta}$-unsaturated ketones to the corresponding saturated alcohols quantitatively. This reduction tolerates many functional groups such as carbon-carbon multiple bonds, chlorides, epoxides, esters, amides and nitriles.