• 제목/요약/키워드: alcohols

검색결과 1,097건 처리시간 0.021초

유기-티탄화학 (제2보). Dichlorodiacetatotitanium (IV) 여러 알콜과의 가용매반응 (Organotitanium Chemistry II. Solvolytic Reaction of Dichlorodiacetatotitanium (IV) with Various Alcohols)

  • 이후성;어용선;손연수;최규원
    • 대한화학회지
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    • 제17권3호
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    • pp.174-181
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    • 1973
  • 이클로리도비스아세테이토 티탄(IV)은 알콜에 녹을 때 화학반응을 일으킨다. $TiCl_2(OAc)_2$의 이러한 가알콜분해 반응을 여러 형태의 알콜에 대하여 반응 용액의 핵자기 공명스펙트럼과 분리된 반응 생성물의 화학분석결과 등을 이용하여 완전히 구명하였다. $TiCl_2(OAc)_2$와 1급 알콜과의 반응은 다음과 같은 2단계의 리간드 치환반응이 정량적으로 일어남을 알았다. $TiCl_2(OAc)_2+ROH{\to}TiCl_2(OAc)_2(OR)+AcOH$, $TiCl_2(OAc)_2(OR)+ROH{\to}TiCl_2(OAc)_2+AcOH$ 또한 $TiCl_2(OAc)_2$가 알콜에 녹을 때 최초의 가용성 분자 형태는 $TiCl_2(OAc)(OR)$임을 알 수 있었다. 3급 알콜과의 가알콜분해 반응은 1급 알콜때와는 상당히 다름을 알 수 있었다. 즉 3급 부칠 알콜과 $TiCl_2(OAc)_2$의 몰비가 1:2이하인 경우에는 다음과 같은 치환 반응만 선택적으로 일어난다. $TiCl_2(OAc)_2+t-ButOH\toTiCl_2(OAc)_2+t-ButCl$그러나 위의 몰비가 1:2이상이 되면 이러한 반응과 병행하여 1급 알콜과의 첫단계 반응과 똑같은 형의 치환 반응이 경쟁적으로 일어남을 발견하였다. 3급 알콜과의 반응이 1급 알콜과의 반응과 또 다른 점은 $TiCl_2(OAc)_2$중의 두 개의 클로리도리간드 또는 두 개의 아세테이토리간드 중 하나만이 3급 부칠알콜의 OH또는 t-ButO기와 치환된다는 사실이다.

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Microwave Mediated Protection of Hindered Phenols and Alcohols

  • Pothi, Tejas;Dawange, Mahesh;Chavan, Kamlesh;Sharma, Rajiv;Deka, Nabajyoti
    • 대한화학회지
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    • 제56권6호
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    • pp.706-711
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    • 2012
  • Hindered phenols and alcohols were protected as their corresponding ethers using different alkylating agents in presence of KOH/DMSO under microwave irradiation. $$R-OH\;{KOH/DMSO,\;R^{\prime}-X,\;MW \\{\vec{10-15\;Mins,\;80%-90%\;Yield}}}\;R^{{/}^O{\backslash}}R^{\prime}$$.

Halogenated Cleavage of Epoxides into Halohydrins in the Presence of a Series of Diamine Podands as Catalyst with Elemental Idoine and Bromine

  • Sharghi, Hashem;Paziraee, Zahra;Niknam, Khodabakhsh
    • Bulletin of the Korean Chemical Society
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    • 제23권11호
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    • pp.1611-1615
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    • 2002
  • The ring opening of epoxides with elemental iodine and bromine in the presence of three diamine podands 7-9 as new catalysts affords vicinal iodo alcohols and bromo alcohols in high yields. This new procedure occurs regioselectively under neutral and mild conditions in various aprotic solvents even when sensitive functional groups are presented.

Novel Asymmetric Synthesis of Unsaturated 1,2-Amino Alcohols

  • Kim, Ji-Duck;Jung, Young-Hoon
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.231.2-232
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    • 2002
  • The synthesis of chiral 1,2-amino alcohols has been an area of intense study in the synthetic and industrial fields, because of their important roles in organic synthesis as fundamental building blocks and their occurrence in a number of natural products. drugs. and chiral auxiliaries or ligands. General methods for the synthesis of these compounds can be divided into two large categories: functional group transformations and the C-C or the C-N bond formations. (omitted)

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A Simple and One-pot Oxidative Conversion of Alcohols or Aldehydes to the Nitriles using NaIO4/KI in Aqueous NH3

  • Zolfigol, Mohammad Ali;Hajjami, Maryam;Ghorbani-Choghamarani, Arash
    • Bulletin of the Korean Chemical Society
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    • 제32권12호
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    • pp.4191-4194
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    • 2011
  • Sodium periodate ($NaIO_4$) and potassium iodide (KI) in aqueous ammonia has been used for the one-pot synthesis of nitriles from the corresponding aldehydes and alcohols in moderate to good yield. This transformation, proceeds via an in situ oxidation- imination-aldimine oxidation sequence.

브롬화벤젠의 알코올에 의한 용매분해에 관한 반응속도론적 연구 (Kinetics of the Solvolysis of Benzyl Bromides in Alcohols)

  • 임용진;여수동;홍순영
    • 대한화학회지
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    • 제15권5호
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    • pp.219-222
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    • 1971
  • The kinetics of the solvolysis of benzyl and p-or m-substituted benzyl bromides in various alcohols have been determined by an electric conductivity method. From these reactions, a curved Hammett plot is obtained and a mechanism is proposed to account for the nonlinear behavior observed. In addition, effects of solvent polarity on the activation parameters for the solvolysis of benzyl bromides are discussed.

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일메나이트 상에서 광화학반응에 의한 유기물의 분해 (Decomposition of Organic Compound by Photo-Chemical Reaction on Ilmenite)

  • 최임규;하백현
    • 태양에너지
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    • 제8권2호
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    • pp.39-45
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    • 1988
  • Photo-decomposition experiments to produce hydrogen from organic compound such as alcohols and organic acids were investigated using the Korean natural ilmenite, which was used as ore itself as well as the calcined in vacuum. The decomposition activities of alcohol on ore (30-60 mesh) which was not calcined did not decrease even if it was repeatedly used. But crushed ore which had newly formed ilmenite surface revealed enhanced activities. The ilmenite powder calcined in vacuum showed 3-8 times higher activies than the ore powder itself and also the decomposition activity of formic acid was much higher than that of alcohols.

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Regiospecific Ring-Opening of Unsymmetrical Epoxides to the Corresponding Less Substituted Alcohols by Newly-Devised Meerwein-Ponndorf-Verley Type Reagents

  • Cha, Jin Soon
    • 통합자연과학논문집
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    • 제5권2호
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    • pp.91-99
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    • 2012
  • A newly-devised Meerwein-Ponndorf-Verley (MPV) reagents, such as diisobutylacetoxyalanes and diisobutylmethanesulfonylalanes, achieved a clean conversion of unsymmetrical epoxides to the corresponding less substituted alcohols. This review covers the recent developments for such a regiospecific ring-opening reaction of epoxides.