• Title/Summary/Keyword: Stereochemical course

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Stereochemical Course of the Reductive Decyanation of Cyclic α-Phenylnitrile. Dependence on the Added Alcohol and Metal of the Decyanation of 4-t-Butyl-1-phenylcyclohexanecarbonitrile

  • 라춘섭;김양숙
    • Bulletin of the Korean Chemical Society
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    • v.18 no.2
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    • pp.151-155
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    • 1997
  • Stereochemical course of the reductive decyanation of two stereoisomeric 4-t-butyl-1-phenylcyclohexanecarbonitriles 3 and 4 using solvated electron has been studied. While sodium-mediated reactions of both 3 and 4 in the presence of alcohols give the same ratio, 1.5 : 1, in favor of the thermodynamically more stable product 5 over the other one 6, the ratios obtained from the potassium-mediated process are found to be very sensitive to the kind of H-donors. When reactions are performed without H-donors, 5 is only obtained from the experiments with both stereoisomers irrespective of the metal species.

Synthesis and Characterization of Dodecanucleotides Containing the XhoI Recognition Sequence with a Phosphorothioate Group at the Cleavege Site

  • 문병조;김상국;김남희;권오신
    • Bulletin of the Korean Chemical Society
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    • v.17 no.11
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    • pp.1031-1036
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    • 1996
  • The synthesis and characterization of diastereomeric dodecanucleotides, d[GATCp(S)TCGAGATC], containing recognition sequence of the XhoI restriction endonuclease with a phosphorothioate internucleotidic linkage the cleavage site are described. Rp and Sp form of diastereomerically pure dinucleoside phosphorothioates d[Cp(S)T] were presynthesized and used for the addition to the growing oligonucleotide chain as a block. The stereochemistry of dinucleoside phosphorothioate was assigned by 31P NMR spectroscopy, enzyme digestion, and reverse-phase HPLC. XhoI restriction endonuclease cut only Rp diastereomer d[GATCp(S))TCGAGATC]. The rate of hydrolysis is slower than that of the unmodified dodecamer d[GATCTCGAGATC]. The phosphorothioate nucleotide is using for determination of the stereochemical course of the XhoI catalyzed reaction.