• Title/Summary/Keyword: asymmetric synthesis

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Microbial styrene monooxygenase-catalyzed asymmetric synthesis of enantiopure styrene oxide derivatives (미생물 유래 Styrene monooxygenase를 이용한 광학활성 styrene oxide 유도체의 비대칭합성)

  • Lee, Eun-Yeol;Park, Sung-Hoon
    • KSBB Journal
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    • v.24 no.3
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    • pp.239-245
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    • 2009
  • Enantiopure styrene oxide derivatives are versatile building blocks for the synthesis of enantiopure pharmaceuticals. Styrene monooxygenase (SMO) catalyzes an asymmetric addition of an oxygen atom into a double bond of vinylaromatic compounds. SMO is a commercially potential biocatalyst to synthesize a variety of enantiopure epoxides with high enantiopurity and recovery yield. In this paper development of SMO biocatalyst and commercial feasibility of SMO-catalyzed asymmetric synthesis of enantiopure stylers oxide derivatives are reviewed.

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 Directed Toward Asymmetric Total Synthesis of Calycotomine (Calycotomine의 입체선택적 합성 연구)

  • Yang, Jung-Eun;Jung, Jae-Kyung
    • YAKHAK HOEJI
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    • v.53 no.3
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    • pp.161-164
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    • 2009
  • Synthetic studies directed toward an asymmetric total synthesis of calycotomine, an representative tetrahydroisoquinoline, are described. The application of N-tert-butane sulfinyl chiral auxiliary to the Pictet-Spengler type reaction for the efficient synthesis of tetrahydroisoquinoline skeleton has been also investigated.

A Study on the Synthesis of a Dual-Mode Asymmetric Canonical Filter (이중모드 비대칭 Canonical 구조 필터의 합성에 대한 연구)

  • 엄만석;이주섭;염인복;이성팔
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.6
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    • pp.599-605
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    • 2003
  • A dual-mode asymmetric canonical filter is widely used in an input demultiplexer for satellite transponder. This paper deals with a simple synthesis method fur an asymmetric canonical filter. The coupling matrix of an asymmetric canonical filter is obtained by applying plane rotation technique to the coupling matrix of a symmetric canonical filter. This paper gives a list of pivots and rotation angles to obtain the coupling matrix of asymmetric canonical structure filters. The coupling matrix of 8th and 10th order asymmetric canonical filter is obtained by this proposed method. It is shown that the frequency response of asymmetric canonical filter is identical to that of symmetric canonical filter.

Design, Synthesis and Catalytic Property of L-Proline Derivatives as Organocatalysts for Direct Aldol Reaction

  • Wang, Lei;Tang, Ruiren;Yang, Hua
    • Journal of the Korean Chemical Society
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    • v.57 no.5
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    • pp.591-598
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    • 2013
  • A series of chiral prolinamide compounds with pyridine-2, 6-dicarboxylic acid moieties derived from L-proline have been designed and synthesized, their catalytic properties for direct asymmetric aldol reactions were also studied in this article. These catalysts gave the aldol product in high yield (87%) and high enantioselectivity, up to 85%, of the anti-structure at room temperature but gave disappointing results at a lower temperature or when additive was added. Conditions, including solvents, temperature and additives were screened for the reactions. Moreover, the influence of presence of water on yield and stereoselectivity was also discussed.