• Title/Summary/Keyword: Diastereoselective

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Diastereoselective Reduction of 2,3-Dioxo-4-carboxy-5-substituted Pyrrolidines Using NaBH4/AcOH and Heterogenous Hydrogenation Reactions

  • Mohammat, Mohd Fazli;Mansor, Nurul Shulehaf;Shaameri, Zurina;Hamzah, Ahmad Sazali
    • Journal of the Korean Chemical Society
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    • v.59 no.1
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    • pp.31-35
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    • 2015

  • Diastereoselective reduction of 2,3-dioxo-4-carboxy-5-(substituted)pyrrolidine 1 by $NaBH_4/AcOH$ and heterogenous hydrogenation were reported. Stereochemical assignment and diastereomeric ratios of the products were determined using $^1H$ NMR and single crystal X-ray analyses. The steric factors of the C-5 substituents of the pyrrolidinone was shown to have an interesting influence on both the yield and diastereoselectivity of the reduced product.

  • https://doi.org/10.5012/jkcs.2015.59.1.31 인용 PDF KSCI KPUBS HTML

Diastereoselective Synthesis of 1,6-Diepicastanospermine from D-Glucono-δ-lactone

  • Jang, Ki-Chang;Choi, Sung-Jun;Kim, Jin-Hyo;Lee, Jin-Hwan;Lee, Byong-Won;Park, Ki-Hun
    • Bulletin of the Korean Chemical Society
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    • v.24 no.7
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    • pp.921-924
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    • 2003

  • Homochiral (-)-pipecolaldehyde 6 from D-glucono- δ-lactone underwent a highly diastereoselective addition upon treatment with vinylmagnesium bromide. Treatment with vinylmagnesium bromide produced antiaminoalcohol 7a which was easily converted into the synthesis of 1,6-diepicastanospermine 2.

  • https://doi.org/10.5012/bkcs.2003.24.7.921 인용 PDF KSCI

Diastereoselective Synthesis of (＋)-Frontalin

  • Jung, Jung-Hwa;Kim, Hee-Doo
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.345.3-346
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    • 2002

  • In connection with the asymmetric synthesis of chiral l.2-diol. we report here the total synthesis of (＋)-frontalin using diastereoselective alkylation featuring tridentate chelation-controlled asymmetric alkylation of a-hydroxyketone, in which the chiral auxiliary is attached to the hydroxyl group as ether linkage. The starting D-glyceraldehyde acetonide was converted (S)- ［(4R)-2.2-dimethyH,3-dioxolan-4-yl］ (4-methoxyphenyl) methanol. (omitted)

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Studies on the Regioselective and Diastereoselective Amination using Chlorosulfonyl Isocyanate (CSI)

  • Kim, In-Su;Jung, Young-Hoon
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.239.2-240
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    • 2003

  • We have recently described the novel synthetic method for N-protected amines from various ethers using chlorosulfonyl isocyanate(CSI) and found that the mechanism of our CSI reaction is a competitive reaction of SN1 and SNi mechanism according to the stability of carbocation intermediate. Forthermore. we developed the regioselective and diastereoselective one-pot synthetic method for 1,2-amino alcohol, through the reaction of di-and tribenzyl thers with CSI, and invetigated its mechanism. (omitted)

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