• Title/Summary/Keyword: Carbonyl group

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Space Charge Behaviors of New Insulating Materials for URD cables (새로운 지중배전케이블용 절연재료의 공간전하 거동)

  • 고정우;서광석;김종은;남윤선;김덕주
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.11a
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    • pp.207-210
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    • 1998
  • Electrical properties such as space charge distribution and electrical conduction of XLPE/VLDPE blends were studied. When the VLDPE is blended, residual charge inside XLPE increases. In case of electrical conduction characteristics, there were no changes in electrical conduction mechanism, space charge limited conduction. XLPE/VLDPE blend including crosslinking coagent showed relatively small current density. It might be due to the carbonyl group in crosslinking coagent.

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Origin of Exo/Endo Selectivity in the Intramolecular Diels-Alder Reaction

  • Yan, Shihai;Ryu, Do-Hyun;Lee, Jin-Yong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2527-2530
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    • 2010
  • The stereoselectivity of the intramolecular Diels-Alder reactions of 1 and its derivatives were investigated by ab initio calculations. The stereoselectivity mainly originates from the steric repulsion and the orbital interactions. The additional s-cis and s-trans conformations by introducing the carbonyl group at the neighbor of diene or dienophile may change the stereoselectivity, hence this kind of substitution can be utilized for stereoselectivive asymmetric synthesis.

Specific Association of Riboflavin and Penicillin Derivatives in Chloroform Solution

  • Yu, Byung-Sul
    • YAKHAK HOEJI
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    • v.18 no.3
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    • pp.209-216
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    • 1974
  • From the measurements of infrared and fluorescence spectra riboflavin-2',3',4',5'-tetraacetate has been found to associate with penicillin-V more than strongly with themselves. They form the 1 : 1 cyclic hydrogen bonded dimer through the imino and the 2-C carbonyl groups of the isoalloxazine ring and the imino group of the penicillin-V ressidue. Pernicillin-V is an effective quencher of the fluorescence of riboflavin through hydrogen bonds partly due to the collision interaction with the penicillin ring.

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Synthesis and Antiviral Activity of Novel Anomeric Branched Carbocyclic Nucleosides

  • Kim, Ai-Hong;Hong, Joon-Hee
    • Archives of Pharmacal Research
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    • v.28 no.10
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    • pp.1105-1110
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    • 2005
  • Novel anomeric branched carbocyclic nucleosides were synthesized from 1,3-dihydroxy acetone. 4'-Hydroxymethyl was installed by [3,3]-sigmatropic rearrangement reaction and 1'-methyl group was introduced by carbonyl addition of methylmagnesium bromide. The coupling of nucleosidic bases and desilylation afforded a series of novel nucleosides. The synthesized compounds $16{\~}19$ were evaluated for their antiviral activity against HIV-1, HSV-1, HSV-2, and EMCV. Compounds 16 and 19 exhibit toxicity non-related to any anti-HIV-1 activity.

Elimination Reaction of $\alpha$-Diethaylaminoacetophenone in the Formation of Hydantoin Derivatives (히단토인 유도체 형성에 있어서 $\alpha$-Diethaylaminoacetophenone의 탈이반응)

  • 권순경
    • YAKHAK HOEJI
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    • v.22 no.4
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    • pp.215-218
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    • 1978
  • It is known that hydantoin derivative can be synthesized according to the method of Bucherer-Bergs, which employs the interaction of the carbonyl compounds with potassium cyanide and ammonium carbonate in dilute alcohol solution. In a converting study of .alpha.-dietylaminoacetophenone with KCN and ($NH_{4})_{2}CO_{3}$ to hydantoin, the attempted 5-diethylaminomethyl-5-phenylhydantoin was not formed. In this reaction diethylaminomethly group was unexpectedly eliminated and 5-phenylhydantoin was obtained, instead of the anticipated compound.

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Carbonylation of Protected or Non-protected 2-Bromobenzaldehyde Catalyzed by Cobalt Carbonyl

  • Sang Chul Shim;Dong Yup Lee;Heung Jin Choi;Chil Hoon Doh;Keun Tai Huh
    • Bulletin of the Korean Chemical Society
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    • v.15 no.9
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    • pp.772-774
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    • 1994
  • The cobalt catalyzed carbonylation of bromobenzene having protected aldehyde group gives the corresponding ester in good yields, but 2-bromobenzaldehyde gives 3-alkoxyphthalide in the noticeable yield instead of alkyl 2-formylbenzoates.

Thermal and Photoinduced Silylallylation Reactions of Organic Halides with 3-Stannyl-2-(silylmethyl)propene

  • 강경태;황성심;곽우영;윤웅찬
    • Bulletin of the Korean Chemical Society
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    • v.20 no.7
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    • pp.801-804
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    • 1999
  • Thermal and photoinduced silylallylation reactions of organic halides with 3-stannyl-2-(silylmethyl)propene are explored. Silylallylations occur in moderate to high yields, producing various functionalized allylsilane products in which halide carbon is bonded to the terminal alkenic carbon of allylsilane with the removal of tributyltin group. The reactions, which tolerate functional groups such as carbonyl, ester, nitrile, acetal, and ketal, hold synthetic potential for the construction of functionalized allylsilanes.

Anchimeric Assistance in the Rearrangement of Dichloro-3-methyl-1,4-oxathianes to 2-Chloromethy1 Dihydro-1,4-oxathiins

  • 한호규;최중권;남기달
    • Bulletin of the Korean Chemical Society
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    • v.19 no.10
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    • pp.1109-1112
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    • 1998
  • An anchimeric assistance of anilide in the rearrangement of dichloro-1,4-oxathaines 1 to 2-chloromethyl dihydro-1,4-oxathiins 2 is described. The inductive effect of the carbonyl group of anilide was negligible in the rearrangement. A rate of the rearrangement depended on the basicity of anilide nitrogen. A hydrogen bonding between the anilide hydrogen and an oxygen atom of those substituents make the nitrogen less basic, resulting in the slower rearrangement.

Adsorption Characteristics of Methylene Blue from Aqueous Solution According to Physical and Surface Properties of Activated Carbons (활성탄의 물리적 특성과 표면 특성에 따른 수중의 methylene blue의 흡착특성)

  • Kam, Sang-Kyu;You, Hae-Na;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.23 no.11
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    • pp.1821-1826
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    • 2014
  • The adsorption characteristics of the methylene blue (MB) were studied using three activated carbons such as ACA and ACB with similar specific surface area (1,185 and $1,105m^2/g$), and ACC with relatively high specific surface area ($1,760m^2/g$). The surface chemical properties of these activated carbons were investigated by X-ray photoelectron spectroscopy (XPS). The results indicated that ACA had more functional groups (with phenol, carbonyl, and carboxyl etc.) than ACB (with carbonyl and carboxyl) and ACC (with carboxyl). The isotherm data were fitted well by Langmuir isotherm model. The adsorption capacities of ACA, ACB, and ACC for MB were 454.7 mg/g, 337.7 mg/g, and 414.0 mg/g, respectively. As phenol and carboxyl content of the surface on activated carbon increased, MB adsorption capacity was increased. Although ACA had a smaller specific surface area than ACC, the content of phenol and carboxyl group was abundant, so MB adsorption capacity was found to be higher than ACC.