• Title/Summary/Keyword: Regioselective

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Total Synthesis of Sufentanil

  • Shin, Dong-Yun;Ryu, Jae-Sang;Hyun, Soon-Sil;Park, Hyun-Ju;Jeon, Ra-Ok;Suh, Young-Ger
    • Archives of Pharmacal Research
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    • v.22 no.4
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    • pp.398-400
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    • 1999
  • Sufentanil, a potent anilidopiperidine analgesic, was synthesized from a simple thiophenylethylamine via six sequence. The key parts of this synthesis involved an efficient construction of thiophenylethylpiperidone by aminomethano desilylation-cyclization followed by Swern oxidation and a direct regioselective N-nucleophilic spiral epoxide cleavage with aniline promoted by Lewis acids.

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Stereoselective Transformation of Phytosphingosine to Safingol

  • Kim, Na-Ri;Lee, Sun-Hee;Namgoong, Sung-Keon
    • Bulletin of the Korean Chemical Society
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    • v.30 no.3
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    • pp.695-699
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    • 2009
  • A short and efficient synthesis of (2S,3S)-safingol from commercially available D-ribo-(2S,3S,4R)-phytosphingosine is described. The highlights of the synthesis are a stereoselective one-pot transformation of a diol into an epoxide under phase transfer catalytic conditions and a regioselective epoxide-opening reduction with a hydride reagent.

Synthesis and Antitumor Activity of Novel Gericudranin E Derivatives (새로운 항암성 제리쿠드라닌 E 유도체의 합성 및 항암활성)

  • 박재호;박경란;호현순;김희두;표명윤
    • YAKHAK HOEJI
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    • v.43 no.5
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    • pp.559-565
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    • 1999
  • The two gericudranin E derivatives, GER-I & II, were synthesized and evaluated their antitumour activities for the elucidation of structure-activity relationship. 2,4,6-Trihydroxyacetophenone was converted to target molecules GER-I and GER-B in 5 steps via sequential protection, aldol condensation, Michael type-cyclization, regioselective C-benzylation. The cellular growth inhibition of compounds GER-I and GER-II were investigated against P388, L1210, K562, HCT-15, SK-HepG-1, MCF-7 as cancer cell lines and mouse splenocytes as a normal cell by MTT assay.

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Photochemistry of Conjugated Poliynes : Photochemical Generation of Silacyclopropenes from 1-Aryl-4-(pentamethyldisilanyl)buta-1,3-diynes

  • 심상철;이성택
    • Bulletin of the Korean Chemical Society
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    • v.16 no.10
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    • pp.988-990
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    • 1995
  • No fluorescence was observed from 1-aryl-4-(pentamethyldisilanyl)buta-1,3-diynes except 1-(1-naphthyl)-4-(pentamethyldisilanyl)buta-1,3-diyne. Irradiation of 1-aryl-4-(pentamethyldisilanyl)buta-1,3-diynes (1) with methanol gives photoaddition products in relatively low yields compared to arylethynyldisilanes which show dual fluorescence. Irradiation of 1 with acetone yields site specific and regioselective 1:1 photoadducts through silacyclopropene intermediates. The triplet excited state of the silacyclopropene reacts with acetone to give addition photoproducts and the triplet energy of the silacyclopropenes lies around 260-286 kJ/mol.

Convenient Route to Core-modified Corroles by Acid-catalyzed Condensation of Furylpyrromethanes and Dipyrromethanes

  • Lee, Chang Hui;Jo, Won Seop;Ga, Jae Won;Kim, Han Jae;Lee, Pil Ho
    • Bulletin of the Korean Chemical Society
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    • v.21 no.4
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    • pp.429-433
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    • 2000
  • Corroles and oxacorroles were synthesized by acid-catalyzed, 2+2 condensation. The condensation afforded different corroles bearing core-heteroatoms at the predesignated locations. Regioselective a- a’ linkage be-tween pyrrole and furan or betwee n pyrrole and pyrrole was achieved by keeping the linking carbon at different position of starting dipyrromethanes. The condensation was only fruitful when furan-containing dipyrromethanes were condensed.

Photochemistry of 1-(o-Hydroxyphenyl)-2-pentamethyldisilanylethyne : Photoreaction in a Concentrated Benzene Solution and Photoreaction with Methanol or Acetone

  • Park, Seong Gi
    • Bulletin of the Korean Chemical Society
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    • v.22 no.11
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    • pp.1202-1206
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    • 2001
  • Irradiation of 1-(o-hydroxyphenyl)-2-pentamethyldisilanylethyne 1 in a concentrated benzene solution has provided photodimer product 7 along with other reported photoproducts. Irradiation of 1 in methanol yields 1-(o-hydroxyphenyl)-2-trimethylsilylethyne 2 and its reduction product 13, via silacyclopropene intermediate 10, and the reduction product 8 and two methanol addition products, 11 and 12, via o-hydroxyphenylethyne. Photolysis of 1 with acetone in deaerated methylene chloride affords site specific and regioselective 1 : 1 adduct 16 via silacyclopropene intermediate 10.

Antifungal activities of juglone and naphthazarine derivatives

  • Chae, Mi-Jin;Choi, Ik-Hwa;Han, Ja-Young;Jong, Ok-Jai;Ryu, Chung-Kyu
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.185.3-185.3
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    • 2003
  • Juglone and naphthazarine derivatives were newly systhesized for the evaluation of antifungal activities. These derivatives were prepared by methylation of juglone and 2, 3-dichloro-5, 8-dihydroxy-l, 4-naphthoquinone, and by regioselective nucleophilic subsitution with arylthiols. All compounds were tested in vitro for their growth inhibitory activities against pathogenic fungi by the standard method. The MIC values were determined by comparison to flucytosine as a standard agent. (omitted)

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Stereoselective Total Synthesis of (-)-Cytoxazone

  • Kim, Ji-Duck;Hoon, Jung-Young
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.179.2-179.2
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    • 2003
  • We have developed the novel one-pot synthetic method for regioselective and stereoselective N-protected amines through the reaction of various ethers with chlorosulfonyl isocyanate (CSI). Also, we found a novel technique to compare directly the stability of carbocations in the solution phase and established the stability order of the various carbocations. And we reported the cleavage of benzyl and p-methoxybenzyl protecting groups of alcohols and phenols in the presence of other functional groups using CSI. (omitted)

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