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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/65085

    Title: 以α,β-不飽和酮進行環丙烷化反應 - 不對稱合成天然物Brevipolide H之鏡像異構物;Asymmetric synthesis of (-)-brevipolide H through cyclopropanation of the α,β-unsaturated ketone
    Authors: 林靖文;Lin,Jing-wen
    Contributors: 化學學系
    Keywords: 環丙烷;交叉置換反應;Sharpless不對稱α-羥基化反應;烯醇矽醚;天然物;α,β-不飽和酮;cyclopropanation;brevipolides;Sharpless asymmetric α-hydroxylation;cross metathesis;cyclopropane;α,β-unsaturated enone
    Date: 2014-08-28
    Issue Date: 2014-10-15 14:40:02 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 本篇論文利用C2對稱的雙烯雙醇化合物2作為起始物,經由交叉置換反應、環丙烷化反應、Sharpless不對稱α-羥基化反應和環閉合置換反應合成天然物brevipolide H的鏡像異構物 (ent-1)。其中天然物的中心結構,是以硫ylide對α,β-不飽和酮5進行環丙烷化反應,形成符合天然物之鏡像異構物的立體位向。此立體結構經由X-ray單晶繞射確定。此外,藉由γ醇上保護基的改變 (乙基甲醚和縮丙酮),可以發展出相反的環丙烷位向;之後再依序與4-甲基肉桂酸進行酯化、與3-丁烯酸進行Mitsunobu反應,建構天然物brevipolide H之鏡像異構物 (ent-1) 右端的4-甲基肉桂酯及左端的5,6-二氫-2-吡喃酮結構。
    ;We utilized the C2 symmetric diene-diol 2 as the starting material, and the skeleton of ent-brevipolide H (ent-1) was prepared by the sequence of cross metathesis, cyclopropanation, Sharpless asymmetric α-hydroxylation and ring-closing-metathesis. The anti-addition of the sulfur ylide to the α,β-unsaturated enone 5 was be developed to generate the key cyclopropane moiety, whose stereochemistry was lated confirmrd by X-ray crystallography. The substrates with different hydroxyl protecting groups, i.e. ethoxymethyl ether and acetonide, lead to the different stereo-assignment of the cyclopropane. The first total synthesis of ent-brevipolide H (ent-1) was achieved after the linkage of 4-methoxycinnamic acid to an ester, the formation of 5,6-dihydro-2-pyrone and deprotection.
    Appears in Collections:[化學研究所] 博碩士論文

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