• Title/Summary/Keyword: Steroselective

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Acyclic Eposidations (II)

  • Kim, Deuk-Joon
    • Archives of Pharmacal Research
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    • v.5 no.2
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    • pp.109-110
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    • 1982
  • Conveersion of vinylogous glycidic ester 1 to 2 by a stereoselective acyclic allylic epoxidation will be presented.

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A Steroselective Synthesis of (22R, 23R)-Methylenecholesterol

  • Kim, Deuk-Joon
    • Archives of Pharmacal Research
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    • v.15 no.4
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    • pp.374-375
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    • 1992
  • The marine sterol (22R, 23R)-methylenecholesterol 1 has been synthesized from readily available C-22 steroidal ester 2 utilizing an intermolecular acyclic ester enolate alkylation as the key step.

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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.

X-ray Crystal Structure of Hetaryl Leuco-TAM Dyes, (2Z,2'E)-2,2'-(2-Phenyl Propane-1,3-diylidene) Bis(1,3,3-trimethyl indoline) Derivatives

  • Keum, Sam-Rok;Roh, Se-Jung;Kim, Young-Nan;Im, Do-Hyuck;Ma, So-Young
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2608-2612
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    • 2009
  • The unequivocal solid-state structure and stereochemistry of the hetaryl leuco-TAM dye, 2,2’-(2-phenyl propane- 1,3-diylidene) bis(1,3,3- trimethylindoline) derivatives were established using X-ray single crystal analysis. The X-ray crystal analysis showed that the (Z, E)-isomers only formed stereoselectively, with a so-called “threebladed propeller” conformation, from the reaction of a Fischer base and benzaldehyde derivatives. These isomers were stacked in a juxtaposition to form a dimer or a double dimer, adopting either a triclinic, with P-1, or monoclinic crystal system with a space group P21/n in the unit cell of the crystal.