• Title/Summary/Keyword: Stereoselective synthesis

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Total Synthesis of Isopimarol Diterpene (Isopimarol Diterpene의 전합성)

  • 서영거;전라옥
    • YAKHAK HOEJI
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    • v.43 no.6
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    • pp.696-702
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    • 1999

  • The first and versatile total synthesis of isopimarol diterpene has been achieved via stereoselective construction of C-13 quaternary carbon unit as a key step. Isopimarol diterpene was synthesized from the known decalone in 17% overall yield of 16 steps.

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Synthesis of The Optically Active Bicyclo [4.2.0. ] octanone by Stereoselective Intramolecular [2+2] Cycloaddition (입체선택적인 분자내 [2+2] 환화반응을 이용한 광학활성 Bicyclo[4.2.0.]octanone의 합성)

  • Shim, Pil-Jong;Kim, Hee-Doo
    • YAKHAK HOEJI
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    • v.41 no.6
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    • pp.714-717
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    • 1997

  • Stereoselective synthesis of the optically active bicyclo [4.2.0] octanone 5 was accomplished using intramolecular olefin-keteniminium salt[2+2]cycloaddition of the amide 4 as a key step. This important chiral synthon was prepared starting from readily available L-glutamic acid via an efficient 8-step sequence.

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A Stereoselective Asymmetric Synthesis of Antibiotic (-)-Fumagillol Using Claisen Rearrangement and Intramolecular Ester Enolate Alkylation as Key Steps

  • Kim Deukjoon;Ahn Soon Kil;Bae Hoon;Kim Hak Sung
    • Archives of Pharmacal Research
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    • v.28 no.2
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    • pp.129-141
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    • 2005

  • (-)-Fumagillol (1), a hydrolysis product of fumagillin, has been synthesized by several group from commercially available 1,2:5,6-di-O-isopropylidene-${\alpha}$-D-allofuranose in a highly stereoselective manner. Chiral centers on C5 and C6 came from D-allofuranose and the asymmetric center on C4 was accomplished by 1,3-chirality transfer using the Claisen rearrangement on a chiral allyl alcohol. Chirality, which is necessary on an epoxide consisting of the spiro-ring system, was diastereoselectively constructed by the well-known reaction, intramolecular ester enolate alkylation (IEEA), which showed that this reaction can be applied to the alpha-alkoxy ester system. The epoxide on the side chain was regioselectively introduced by the difference between the number of substituents on the vinyl groups. This accomplishment proved that IEEA can be a useful tool for the synthesis of complex molecules.

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