• 제목/요약/키워드: $\alpha$-Keto ester

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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
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    • 제31권10호
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    • pp.2776-2782
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    • 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.

  • https://doi.org/10.5012/bkcs.2010.31.10.2776 인용 PDF KSCI

${\alpha}$-Diketone 또는 ${\alpha}$-keto ester기를 포함하는 신규 벤젠술포닐우레아 유도체의 합성 및 제초활성 (Synthesis and herbicidal activity of new benzenesulfonylurea derivatives possessing ${\alpha}$-diketone or ${\alpha}$-keto ester moiety)

  • 고영관;장해성;류재욱;우재춘;구동완;김진석;김대황
    • 농약과학회지
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    • 제2권3호
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    • pp.147-150
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    • 1998

  • Ortho치환체로서 ${\alpha}$-diketone 또는 ${\alpha}$-keto ester기를 포함하는 신규한 벤젠 술포닐우레아 유도체들을 2-homophenyl metholernethyl sulfide를 출발물질로 하는 새로운 합성방법을 이용하여 합성하였으며, 이 화합물들은 특히 경엽처리에서 흥미있는 제초활성을 나타내었다.

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A Versatile Synthesis of α-Keto (cyanomethylene)triphenylphosphorane Ylides from Alkyl Halides Utilizing a Noble Phenylsulfonyl Reagent

  • Lee, Kieseung;Hwang, Chan-Yeon
    • Bulletin of the Korean Chemical Society
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    • 제34권10호
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    • pp.2953-2958
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    • 2013

  • A noble phenylsulfonyl reagent 8 having ${\alpha}$-oxo (cyanomethylene)triphenylphosphorane ylide subunit readily condensed with various alkyl halides under basic conditions to afford ${\beta}$-alkyl-${\alpha}$-oxo-${\beta}$-phenylsulfonyl (cyanomethylene)triphenylphosphorane ylides 9 in excellent yields. These sulfonyl ylides 9 were then reductively desulfonylated with $Na(Hg)/Na_2HPO_4$ in the presence of methanol to provide ${\alpha}$-keto (cyanomethylene)-triphenylphosphorane ylides 2' in good to excellent yields. Our new synthetic approach offers an expeditious access to various ${\alpha}$-keto (cyanomethylene)triphenylphosphorane ylides from alkyl halides utilizing a new phenylsulfonyl reagent as the key reagent under mild reaction conditions in good overall yields.

  • https://doi.org/10.5012/bkcs.2013.34.10.2953 인용 PDF KSCI

Studies on Triterpenoid Corticomimetics

  • Han, Byung-Hoon;Han, Yong-Nam;Kim, Tae-Hee
    • 생약학회지
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    • 제17권2호
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    • pp.178-183
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    • 1986

  • It was our working hypothesis that introduction of 11-keto groups to 12-oleanene/ursene series of triterpenoids should endow them with corticoid-like activities, since pharmacological actions of glycyrrhetinic acid (GA) are known to be caused by inhibition on $corticoid-{\delta}^4-reductase$. 11-Keto-triterpenoids derived artificially in these studies, such as 11, 19-diketo-18, 19-secoursolic acid methyl ester(I), $11-keto-{\beta}-boswellic$ acid derivatives (IIa-IIc), 11-Keto-presenegenin dimethyl ester (III), II-keto-oleanolic acid derivatives (IVa-IVd) and 11-keto-hederagenin (V) possess the fundamental functions of ${\alpha},\;{\beta}-unsaturated$ ketone on C-11 and hydroxyl group on C-3, as like GA (VI). Additionally, they involve the carboxyl groups on rings A (II, III), D (I, III, IV, V) and E (VI), and the hydroxyl groups on rings A (III, V) and C (III). All the compounds competitively inhibited $corticoid-5{\beta}-reductase$, and the highest inhibitory potency appeared in I. All of them except $3,\;11-diketo-{\beta}-boswellic$ acid methyl ester (IIc) were more effective about five times to twice than GA. On carrageenin-induced edema test, compounds I and IVa-IVd showed anti-inflammatory activities, but III enhanced rather edema. Structure-activity relations were found in the aspects of hydrophilicity of ring A and hydrophobicity of rings C/D. The more they were hydrophilic in ring A and hydrophobic in rings C/D, the more they inhibited the enzyme. And the more they were hydrophobic in rings C/D, the more they exhibited antiiflammatory activities. However, the increased hydrophilicity in ring A resulted in increasing edema, probably due to a nonspecific inhibition on $aldosterone-5{\beta}-reductase$.

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Purification of ${\alpha}$-Keto Ester Reductase

  • Jin, Sun-Young;Kim, Yun-Jung;Park, Jong-Ok;Kim, Kyung-Soon
    • 한국생명과학회:학술대회논문집
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    • 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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    • pp.36.2-36.2
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    • 2007

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