• Title/Summary/Keyword: aldol condensation

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Aldol Condensation over Acid-Base Bifunctional Metal-Organic Framework Catalysts (산, 염기 이원기능 금속-유기 구조체 촉매를 이용한 알돌 축합반응)

  • Chung, Young-Min
    • Clean Technology
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    • v.20 no.2
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    • pp.116-122
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    • 2014
  • Various types of MOFs (metal-organic frameworks) were prepared via hydrothermal and post-grafting methods and applied as catalysts for the synthesis of jasminaldehyde, one of the representative perfume intermediates, by Aldol condensation of benzaldehyde with heptanal. Although both acid and base sites could catalyze the reaction, the catalytic performance was strongly dependent on the physical properties as well as the nature of functionalization on MOFs. While the use of sulfonated MOF catalysts led to decrease of jasminaldehyde selectivity regardless of MOFs used, the selectivity change was found to rely on the MOF types in the case of the amine-functionalization. Among the catalysts tested, MIL-101 shows the best catalytic performance, which may suggest that MIL-101 has suitable acid properties to promote the Aldol condensation and the large pore of MIL-101 is also advantageous to alleviate the diffusion problem of bulky products.

Stereoselective Crossed-Aldol Condensation of Hetarylmethyl Ketones with Aromatic Aldehydes in Water : Synthesis of (2E)-3-Aryl-1-hetarylprop-2-en-1-ones

  • Basaif, Salem A.;Sobahi, Tatiq R.;Khalil, Ali Kh.;Hassan, Mohamed A.
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1677-1681
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    • 2005
  • Aldol condensation of 2-acetylthiophene, 2-acetylpyrrole and 2-acetylpyridine with different aromatic aldehydes were carried out in water in heterogeneous phases in the presence of cetyltrimethylammonium bromide as cationic surfactant at room temperature. All the reactions occur in a short time with excellent yields of steroselective hetarylpropanones in water as environmental friendly solvent.

Studies on Triterpenoid Corticomimetics (IV) - E-Ring Opening of Pomolic Acid by Retrograde Aldol Condensation

  • Han, Yong-Nam;Han, Byung-Hoon;Park, Eun-Tae;Kim, Tae-Hee
    • Archives of Pharmacal Research
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    • v.8 no.4
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    • pp.221-227
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    • 1985
  • Acetyl-11-ketopomolic acid methyl ester (VI), mp 276-$278^{\circ}$ was synthesized from pomolic acid (III). The mild alkaline treatment of VI induced the opening of ring E on carbone skeleton to yield VII, and then VII was deacetylated to give VIII, mp 82-$84^{\circ}$ Compound VIII was established as 11, 19-diketo-18, 19-secoursolic acid methylester. The E-ring opening was believed to be due to regrograde aidol condensation.

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First Total Synthesis of Prorepensin with a Bis-Geranylated Chalcone

  • Jung, Eun-Mi;Lee, Yong-Rok
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2563-2566
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    • 2009
  • The first total synthesis of naturally occurring prorepensin with a bis-geranylated chalcone has been achieved by a convergent sequence. The key strategy involved in the synthesis of prorepensin was chalcone formation by aldol condensation of the corresponding geranylated acetophenone with geranylated benzaldehyde.

Synthesis and NMR Studies of (E)-1-Aryl-3-(2-pyrrolyl)-2-propenones and (E)-3-Aryl-1-(2-pyrrolyl)-2-propenones

  • Han Lee, In-Sook;Jeoung, Eun Ji;Lee, Chang Kiu
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.936-942
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    • 2013
  • Series of (E)-1-aryl-3-(2-pyrrolyl)-2-propenones, that were aldol condensation products between pyrrole-2-carbaldehyde and m- and p-substituted acetophenones, were prepared and their $^1H$ and $^{13}C$ NMR spectra were examined to obtain the information on the conformation of the enone system. Similar studies were carried out with (E)-3-aryl-1-(2-pyrrolyl)-2-propenones that were prepared from 2-acetylpyrrole and m- and p-substituted benzaldehydes. The substituent chemical shifts were studied by applying the Hammett relationship.

Synthesis of Odorants p-Mentha-8-ene-2-one Derivatives by the Reaction of Dihydrocarvone with Formaldehyde (p-Mentha-8-ene-2-one계 향료합성)

  • 유충규;송기춘
    • YAKHAK HOEJI
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    • v.35 no.4
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    • pp.335-340
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    • 1991
  • The synthetic product of 1-hydroxymethyl-p-mentha-8-ene-2-one was afforded by the reaction between dihydrocarvone and formaldehyde. This reaction involves the aldol condensation. The preferential position of formaldehyde is methyl substituted .alpha.-carbon atom where these enols are regiospecifically formed. The hydroxymethylation of dihydrocarvone was also proved to happen regiospecifically in the position of .alpha.-methyl substituted ketone. When 1-hydroxymethyl-p-mentha-8-ene-2-one reacted with LiAIH$_{4}$, 1-hydroxymethyl-p-mentha-8-ene-2$\beta$-ol obtained. 1-Hydroxymethyl-p-mentha-8-ene-2-one reacted with PDC and chromic acid to give 1-formyl-p-mentha-8-ene-2-one and 1-carboxy-p-mentha-8-ene-2-one. When the hydroxymethyl group of 1-hydroxymethyl-p-menta-8-ene-2-one was reducted to methyl group, 1-methyl-p-menta-8-ene-2-one was obtained. Some of these new compound have certain odor. I, II have woody aroma and IV, V have camphory odors. IX has flowery minty odor.

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A study of aldol condensation reaction product using a microreactor (마이크로 반응기를 적용한 알돌 축합반응 생성물 제조연구)

  • Kim Young-Jun;Lee Sang-Seo;Son Sung-Kwang;Song Kwang-Ho;Choe Jae-Hoon
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.543-544
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    • 2006
  • 3-methyl-2-cyclopentenone is a valuable reaction intermediate for various high value added products. 3-methyl-2-cyclopentenone is not only expensive but also difficult to produce. 3-methyl-2-cyclopentenone can be synthesized by base catalyzed intermolecular aldol condensation. In this work, we studied a simple and practical method for synthesizing 3-methyl-2-cyclopentenone. Experimental results showed the advantages of the continuous flow process using a microreactor with kenic mixers for the synthesis of 3-methyl-2-cyclopentenone.

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