• 제목/요약/키워드: ester synthesis

검색결과 433건 처리시간 0.023초

우로칸 알킬에스테르의 합노(合盧) 및 광학효과(光學效果) (The Synthesis of Urocanic Alkyl Ester and Photolysis)

  • 노승호;이향우;남기대
    • 한국응용과학기술학회지
    • /
    • 제8권1호
    • /
    • pp.45-49
    • /
    • 1991
  • The synthesis of urocanic acid which was started D-fructose, and its alkyl esters, urocanic ethyl ester and urocanic isobutyl ester, were prepared by esterificated. Urocanic ethyl ester and urocanic isobutyl ester were insoluble in water and soluble most organic solvents (ethanol, benzene, toluene, pyridine, THF, DMF) which adds to their practical applicability, and absorb ultraviolet light of greater wavelength than the free acid and there by are more effective for shielding sensitive materials, including the humanbody, from the chemically most effective portion of the solar ultraviolet spectrum.

Melandrin의 합성 (Synthesis of Melandrin)

  • 문정술;이강노;임중기;우원식
    • 약학회지
    • /
    • 제35권4호
    • /
    • pp.332-334
    • /
    • 1991
  • The synthesis of melandrin has been accomplished in good yield by the reaction of 5-tosyloxyanthranilic acid ethyl ester with p-acetoxybenzoyl chloride, followed by removal of protecting groups with methanolic ammonia.

  • PDF

Fenbufen-Acetaminophen Ester의 합성 및 항염 작용 (Synthesis and Anti-inflammatory Activity of Fenbufen-Acetaminophen Ester)

  • 서정진;이종욱
    • 약학회지
    • /
    • 제28권1호
    • /
    • pp.17-20
    • /
    • 1984
  • Synthetic procedures to synthesize fenbufen-acetaminophen ester were searched by acid chloride method, DCC method and mixed acid anhydride method. The compound was synthesized by DCC method and mixed acid anhydride method but could not be synthesized by acid chloride method. Its anti-inflammatory activity was superior to acetaminophen and similar to fenbufen.

  • PDF

A Stereoselective Asymmetric Synthesis of Antibiotic (-)-Fumagillol Using Claisen Rearrangement and Intramolecular Ester Enolate Alkylation as Key Steps

  • Kim Deukjoon;Ahn Soon Kil;Bae Hoon;Kim Hak Sung
    • Archives of Pharmacal Research
    • /
    • 제28권2호
    • /
    • pp.129-141
    • /
    • 2005
  • (-)-Fumagillol (1), a hydrolysis product of fumagillin, has been synthesized by several group from commercially available 1,2:5,6-di-O-isopropylidene-${\alpha}$-D-allofuranose in a highly stereoselective manner. Chiral centers on C5 and C6 came from D-allofuranose and the asymmetric center on C4 was accomplished by 1,3-chirality transfer using the Claisen rearrangement on a chiral allyl alcohol. Chirality, which is necessary on an epoxide consisting of the spiro-ring system, was diastereoselectively constructed by the well-known reaction, intramolecular ester enolate alkylation (IEEA), which showed that this reaction can be applied to the alpha-alkoxy ester system. The epoxide on the side chain was regioselectively introduced by the difference between the number of substituents on the vinyl groups. This accomplishment proved that IEEA can be a useful tool for the synthesis of complex molecules.

Fluorine Labeling in Biosynthetic Studies (I) : Synthesis of Fluorfarnesols

  • Park, O-Sook
    • Archives of Pharmacal Research
    • /
    • 제9권4호
    • /
    • pp.237-242
    • /
    • 1986
  • The Synthesis of E, E, E-12-fluorofarnesol and E, Z-6-fluorofarnesol which are key intermediates for the study of biosynthesis of some sesquiterpenes, is described. E, E-Farnesyl acetate is treated with selenium dioxide to give E, E, E-12-hydroxy farnesyl acetate, whih is transformed by DAST into E, E, E-12-hydroxy farnesyl acetate, which is transformed by DAST into E, E, E,-12-fluorofarnesylacetate. The latter compound is hydrolyzed to E, E, E,-12-fluorofarnesol. The reformatsky reaction of 6-methyl-5-hepten-2-one with ethyl bromofluoroacetate affords ethyl 2-fluoro-3-hydroxy-3, 7 dimethyl-6-octanoate. This ester is acetylated and eliminated to give ethyl (Z)-2-fluoro-3, 7-dimethylocta-2, 6-dienoate, which is transformed to allyl bromide via allylic alcohol. The allyl bromide is treated with dianion of methyl acetate to give-keto ester. The $\beta$-keto ester is converted to diethyl phosphoryloxy compound. The conjugate addition of lithium dimethylcuprate to the latter compound gives fluoro ester, which is treated with DIBAL to afford E, Z-6-fluorofarnesol.

  • PDF

A New Synthesis of Triphenylphosphorane Ylide Precursors to α-Keto Amide/Ester and Tricarbonyl Units via Horner-Wadsworth-Emmons Reaction

  • Lee, Kie-Seung
    • Bulletin of the Korean Chemical Society
    • /
    • 제31권10호
    • /
    • pp.2776-2782
    • /
    • 2010
  • Newly developed Horner-Wadsworth-Emmons (HWE) reagents 5 having triphenylphosphorane ylide subunits readily condensed with various carbonyl compounds under mild reaction conditions to afford $\beta,\gamma$-unsaturated $\alpha$-keto triphenylphorane ylides in good to excellent yields, which were hydrogenated over Pd-C (10%)/$H_2$ (1 atm) to give the corresponding $\alpha$-keto triphenylphorane ylides in quasi-quantitative yields. These triphenyphosphorane ylides have been utilized as the precursors to $\alpha$-keto amide/ester and vicinal tricarbonyl units in Wasserman's synthetic protocols, and have previously been prepared only from carboxylic acids/acid chlorides. Our new approaches provide excellent alternatives for the synthesis of triphenylphosphorane ylide precursors to $\alpha$-keto amide/ester and vicinal tricarbonyl units directly from carbonyl compounds in good to excellent yields.

Cefazolin Butyrolactone Ester의 합성 및 생물약제학적 연구 (Synthesis and Biopharmaceutical Studies of Cefazolin Butyrolactone Ester, a Novel Prodrug of Cefazolin)

  • 이진환;조행남;최준식
    • 약학회지
    • /
    • 제47권5호
    • /
    • pp.331-338
    • /
    • 2003
  • A butyrolactone ester of cefazolin (CFZ-BTL) was synthesized by the esterification of cefazolin (CFZ) with $\alpha$-bromo-${\gamma}$-butyrolactone. The synthesis was confirmed by the spectroscopic analysis. The CFZ-BTL was more lipophilic than the CFZ when assessed by n-octanol/water partition coefficients at various pH. The CFZ-BTL itself did not show any antimicrobial activity in vitro, but after oral administration of CFZ-BTL to rabbits, exerted significant anti-microbial activity in serum samples when measured by the inhibion zone method in nutrient agar plates, due to conversion of CFZ-BTL to an active metabolite, probably CFZ, in the body. The CFZ-BTL was also converted into CFZ as confirmed by in vitro incubation study, with tissue homogenates (liver, blood and intestine) of rabbits. The liver showed the fastest conversion rate, probably via the hydrolysis mechanism. In vivo metabolism of CFZ-BTL to CFZ was also confirmed in vivo serum samples by HPLC. The oral bioavailability of CFZ-BTL in rabbits was 1.6-fold increased when compared to CFZ, resulting from followed by enhanced lipophilicity increased passive absorption in the intestine.

폴리글리세린지방산에스터의 최근 연구동향(제1보) (Recent Trends in Research of Polyglycerin Fatty Acid Esters)

  • 랑문정
    • 한국응용과학기술학회지
    • /
    • 제36권4호
    • /
    • pp.1443-1459
    • /
    • 2019
  • 리글리세린지방산에스터 비이온계면활성제는 식품 등에 오래전부터 사용해 왔으며 PEG계 비이온계면활성제의 안전성 문제에 대한 대안으로 제시되고 있다. 폴리글리세린지방산에스터 계면활성제는 친수기인 폴리글리세린과 친유기인 지방산을 결합시켜 합성된다. 친수기인 폴리글리세린은 글리세린, 글리시돌, 에피클로로히드린 등을 이용하여 중합되는 데 폴리글리세린 중합반응의 주요 이슈는 분기·환상형태가 아닌 직쇄형태의 폴리글리세린의 함량을 높이고 중합도의 분포를 좁히는 것이다. 친수기인 폴리글리세린에 지방산계 친유기를 결합시키는 방법에는 에스터화 반응 등의 화학적 합성법과 지방분해효소를 이용한 효소 합성법이 있다. 폴리글리세린지방산에스터 합성의 주요 이슈는 에스터화정도를 조절하면서 반응수율을 높이고 부반응을 억제하는 것이다.