• 제목/요약/키워드: Ketone

검색결과 656건 처리시간 0.021초

Singlet-Triplet Reactivity of 1-Methyl-2-Cyclohexenyl Aryl Ketones : Racemization vs 1,3-Acyl Shift in the Excited States

  • Woo Ki Chae;Mi Young Chae;Mi Kyung Park;Chung Hee Lee;Eun Hee You
    • Bulletin of the Korean Chemical Society
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    • 제11권3호
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    • pp.241-244
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    • 1990
  • The photochemistry of 1-Methyl-2-cyclohexenyl aryl ketones (phenyl ketone 7a, p-toluyl ketone 7b, biphenyl ketone 7c and -naphthyl ketone 7d) is reported. The aryl ketone 7a, 7b and 7c undergo photo-racemization with efficiencies of 0.75, 0.79 and 0.76 respectively on direct irradiation. Direct irradiation of the ketone 7d, however, undergoes 1,3-shift with an efficiency of 0.02. Triplet states are responsible for the racemizations and singlet state is responsible for 1,3-shift as in general. The ketone 7a, 7b and 7c are good example of a few ${\beta},{\gamma}$-unsaturated ketones which undergo efficient intersystem crossing on direct irradiation.

Effect of Spreading of Neutral Sizing Agent, Alkylketene Dimer, on Sizing Development

  • Seo Won-Sung;Shin Jong-Ho;Cho Nam-Seok
    • 펄프종이기술
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    • 제37권5호통권113호
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    • pp.1-7
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    • 2005
  • The objective of this work was to investigate the effect of spreading behavior of the sizing agents (AKD or dialkyl ketone) on the sizing development of AKD-sized paper. There was a direct relationship between the spreading behavior of the sizing agents and their melting points. Both AKD and dialkyl ketone showed no substantial spreading until the temperature reaches to their melting points. Consequently, dialkyl ketone did not provide sizing development when the paper was heat-treated below $75^{\circ}C$, while AKD provided sizing effect even the paper heated at $50^{\circ}C$. The ketone, however, provided rather higher sizing effect than that of AKD, when the paper was heat-treated over $100^{\circ}C$. This result means that the ketone also gives sizing development to paper, moreover the ketone could give higher sizing effect to paper than AKD when it was melted and well spreaded on the fiber surface. While the ketone introduced to papers from hydrolyzed AKD emulsion could not contribute to sizing development.

C-C Bond Cleavage of 8-Quinolinyl Alkyl Ketone by $\sigma,\eta^{3-}$-Allyl Rhodium(III) Complex

  • 이대윤;임영권;전철호
    • Bulletin of the Korean Chemical Society
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    • 제18권8호
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    • pp.824-827
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    • 1997
  • Bis(ethylene)rhodium(Ⅰ) chloride dimer reacted with vinylcyclopropane to give σ,η3-allylrhodium(Ⅲ) complex 3. Complex 3 underwent C-C bond cleavage of 8-quinolinyl ethyl ketone 11, to form η3-1,3-dimethylallylrhodium(Ⅲ) complex 8, which was reductively eliminated by trimethyl phosphite to give 8-quinolinyl-1-methylbut-2-enyl ketone (10). More sterically hindered 8-quinolinyl alkyl ketones were allowed to react with complex 3 to afford corresponding alkenes as well as a mixture of complex 8 and η3-1-ethylallyl rhodium(Ⅲ) complex 19, identified as 10 and 8-quinolinyl-pent-2-enyl ketone (20) after reductive elimination. 8-Quinolinyl alkyl ketone bearing a sterically hindered alkyl group showed less reactivity for C-C bond cleavage and higher 20/10 ratio compared with those having a less sterically hindered alkyl group, such as 8-quinolinyl ethyl ketone (11).

Correlation of ketone bodies in blood and spleen

  • Sookyung Jeon;Sumin Lee;Wooyong Park;Chihyun Park;Minjung Kim
    • 분석과학
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    • 제36권4호
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    • pp.170-179
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    • 2023
  • Starvation, diabetes, alcoholism and hypothermia cause ketoacidosis in the human body; therefore, the cause of death can be determined by analyzing ketone bodies in the blood of the deceased. In the case of decomposition of the cadaver, however, since collecting intact blood is impossible, ketone body analysis is performed using the spleen. However, the index for diagnosing ketoacidosis is based on blood concentration, and its correlation with ketone bodies present in the spleen remains unknown. In particular, since decomposition proceeds rapidly during summer, when temperature and humidity are high, understanding the correlation between ketone bodies in the blood and spleen is important to estimate the state at the time of death from a decaying body. Therefore, in the present study, the correlation between ketone bodies in the blood and spleen of the deceased was explored. Ketone bodies (beta-hydroxybutyric acid [BHB] and acetone) in the blood and spleen were analyzed and compared from autopsies (>100 mg·L-1 BHB, blood basis) conducted at the Daejeon Forensic Research Institute from June to December 2021. Moreover, the concentration of ketone bodies in the spleen juice and tissues was compared assuming the scenario of extreme decomposition. Ketone retention concentration in the blood and spleen was positively correlated, and the ratio of BHB concentration in the spleen to BHB concentration in the blood ranged from 0.52 to 1.08 (mean = 0.85 ± 0.12), although the ratio may vary depending on the degree of decomposition of the corpse.

2-Furytriisopropoxytitanium의 합성 및 카르보닐 화합물에 대한 반응성 (The Synthesis of 2-Furyltriisopropoxytitanium and its Reactivity to Carbonyl Compounds)

  • 구두효;경석현
    • Applied Biological Chemistry
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    • 제39권4호
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    • pp.309-314
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    • 1996
  • 2-Furyltriisopropoxytitanium은 chlorotaniumtriisopropoxide를 이용하여 2-furyllithium을 금속 전이(transmetallation)시킴으로써 합성되었다. 이 화합물은 실온에서 분리되고 수 주일 동안 $-10^{\circ}C$에서 보존할 수 있었다. 카르보닐 화합물에 대한 2-furyltriisopropoxytitanium의 반응성이 높다는 것을 알았다. 알데히드와 케톤 1:1 혼합물과의 경쟁 반응에서 이 화합물은 완벽한 알데히드 선택성을 나타내었다. 또한, 케톤과 케톤 1: 1 혼합물과의 경쟁반응에서도 이 화합물은 케톤-케톤 구별정도가 상당했다. 케톤-에스테르 작용기에 대한 반응에서 이 화합물은 단지 케톤기와만 반응하였다.

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A Study for the Standardization of Elsholtzia ciliata (Thunb.) Hylander and Elsholtzia splendens Nakai ex F. Maekawa

  • 윤종성;이상인;이재성;박호군
    • 대한한의학회지
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    • 제19권1호
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    • pp.19-26
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    • 1998
  • The purpose of present study is to clarify the differences between EIslwitzia Ciliata (Thunb.) Hylander(향유) and Elsholtzia splendens Nakai ex F. Maekawa (꽃향유) for standardization and the proper usage as medicinal herbs. The major ingredients of both species were isolated by distillation and extraction. The qualitative and quantitative analyses of major distillates were carried out by the use of GC/MS. There was a significant difference between the components of Elsholtzia ciliata and Elsholtzia splendens in the aspects of major components. Several common ingredients were identified as linalool, cumene, elsholtzia ketone, naginata ketone isomer, naginata ketone, myristicin, and sesquiterpene alcohol. Comparison between Elsholtzia. ciliata and Elsholtzia splendens was done in the aspect of major compounds. Myristicin (33.7%) has been shown to be the major component in Elsholtzia ciliata whereas naginata ketone isomer (26.1%) was believed to be a major ingredient in Elsholtzia splendens. The elsholtzia ketone was also one of the major differentiating factors between Elsholtzia splendens and Elsholtzia ciliata, and the quantity is 15.1% in Elslwltzia splendens compared to 2.87% in Elsholtzia ciliata. Moreover, in the Elsholtzia splendens, 4- vinylguaiacol and isoosmorhizole were absent, but both compounds were present in the EIsholtzia ciliata.

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The Effect of Iron Catalysts on the Formation of Alcohol and Ketone in the Biomimetic Oxidation of Cyclohexane

  • Kim Seong-Bo;Lee Kyu-Wan;Kim, Yong-Joon;Hong Seog-In
    • Bulletin of the Korean Chemical Society
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    • 제15권6호
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    • pp.424-427
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    • 1994
  • Effects of iron compounds in known biomimetic oxidation systems (Gif IV and GoAgg II) have been studied on activity and ketone/alcohol selectivity of cyclohexane oxidation. Both ketone/alcohol ratio and cyclohexane conversion were affected by counter-ion Z of iron compounds Z-Fe. When Z has a more electron withdrawing property, the reactivity is increased and the formation of ketone is favored. From these experimental results, a new mechanism is proposed for the biomimetic oxidation system.

cis-trans Isomeric and Substituent Effects on the Lanthanide Induced Shifts in 2-Phenylcyclopropanic System

  • So, Jung-Ho;Cho, Nam-Sook
    • Bulletin of the Korean Chemical Society
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    • 제5권6호
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    • pp.226-230
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    • 1984
  • LIS's of cis and trans-methyl-2-phenylcyclopropanecarboxylate, cis and trans-t-butyl-2-phenylcyclopropanecarboxylate, cis and trans-N,N-dimethylcyclopropanecarboxamide, trans-2-phenylcyclopropyl methyl ketone and trans-2-phenylcyclopropyl t-butyl ketone have been studied. The LIS's hold the McConnell-Robertson relation and are mainly influenced by the steric effect. LIS's of trans isomers are larger than those of cis isomers. In trans isomers, the LIS's decrease in the following order: methyl ketone > methyl ester > N,N-dimethyl amide > t-butyl ketone${\sim}$t-butyl ester.

황산의 첨가에 따른 Methyl Ethyl Ketone Peroxide의 열분해 특성에 관한 연구 (A Study on the Characteristics of Pyrolysis of Methyl Ethyl Ketone Peroxide with Addition of Sulfuric Acid)

  • 정두균;최재욱;이인식
    • 한국화재소방학회논문지
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    • 제18권4호
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    • pp.52-56
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    • 2004
  • Methyl Ethyl Ketone Peroxide의 열분해 특성을 파악하기 위하여 TG-DIA의 실험장치를 사용하여 공기 분위기 중에서 실험을 하였다. 그 결과 MEKPO에 98% H₂SO₄의 첨가량이 증가할수록 분해개시온도는 낮아졌으며, MEKPO의 열분해 최대온도는 116.8℃였다. 미분법에 의하여 얻어진 값으로부터 구한 활성화 에너지는 MEKPO와 MEKPO에 98%H₂SO₄ 1%, 3%, 5%를 첨가했을 경우에 각각 0.576㎉/㏖, 0.355㎉/㏖, 0.284㎉/㏖ 및 0.258㎉/㏖을 구하였다.

직접메탄올 연료전지용 Poly(ether sulfone)/Sulfonated Poly(ether ether ketone) 블렌드 막의 특성 연구 (Characterization of Polymer Blends of Poly(ether sulfone)/Sulfonated Poly(ether ether ketone) for DMFC)

  • 천훈상;이충곤;홍성욱
    • 공업화학
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    • 제16권1호
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    • pp.144-149
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    • 2005
  • Poly(ether ether ketone)을 설폰화시킨 후 poly(ether sulfone) (PES)과 다양한 조성으로 혼합하여 블렌드 막을 제조하였고, 직접메탄올 연료전지(DMFC; Direct Methanol Fuel Cell)용 고분자 전해질 막으로의 응용 가능성을 살펴보기 위하여 조성의 변화에 따른 메탄올 투과도, 수소 이온 전도도, 이온 교환 용량, 그리고 함수율의 변화를 살펴보았다. Sulfonated poly(ether ether ketone) (SPEEK)의 경우 수소 이온 전도도는 비교적 우수하였으나 메탄올 투과도 역시 비교적 높았다. 그러나, PES의 양이 증가함에 따라 수소 이온 전도도보다 메탄올 투과도가 급격히 감소하여서 PES의 양이 40%일 때 가장 좋은 선택성을 나타내었다.