第一部份 天然物Axamide-1, Axisonitrile-1與cis-Dracunculifoliol之全合成研究, 第二部份 微波加熱應用於α-碘基酮之自由基環化反應研究

郭原良(Yuan-Liang Kuo)

指導教授 ： 沙晉康

國立清華大學/理學院/化學系/博士(2008年)

摘要

本論文分成兩個部分：第一部份為利用化合物89經由自由基環化反應建構天然物axamide-1, axisonitrile-1與cis-dracunculifoliol中的6,5-順式駢環骨架。經由去矽基後我們可於駢環骨架中的六員環上建構一環外雙鍵(化合物90)。此一化合物再經由還原反應、取代反應可以得到一有腈基化合物91。將化合物91經由連續的烷基化-還原反應可以得到化合物92，最後再經過官能基轉換即可得到axamide-1, axisonitrile-1。同時化合物90也可經由Wittig反應與水解反應得到化合物106，最後藉此得到cis-dracunculifoliol。
第二部分為將a-碘基酮置於微波加熱的環境下進行自由基環化反應。與傳統的反應相比，微波高熱促使碘化物無須藉助有機錫試劑的催化即可進行環化反應，同時也伴隨著明顯的1,5-氫轉移現象的發生而產生新的產物。我們也比較在不同溶劑下環化反應能否進行，並發現環化反應在水溶液中也可進行。除此之外a位置接有丙二烯側鏈的碘化物其反應速率會高於接有三鍵的化合物。

關鍵字

a-碘基酮 ； 自由基環化反應 ； 天然物 ； 全合成 ； 微波加熱 ； 1,5-氫轉移

並列摘要

There are two parts in this thesis. In the first part we want to mention the racemic total synthesis of axamide-1, axisonitrile-1 and cis-dracunculifoliol. Radical cyclization of 89 furnished the cis-hydrindanone core. Subsequently desilylation of 96 afforded an exo-double bond in the backbone 90. Compound 90 is a potential synthetic intermediate for this class of natural product. This was followed by reduction, mesylation and substitution. After tandem alkylation-reduction of nitrile 91 and the secondary amine was formed. Finally, the synthetic route was accomplished by formylation of the amine and axisonitrile-1 was made by dehydration of compound 1. By the way, we also used compound 90 as a starting material. After Wittig reaction and hydration of 90, then we could made aldehyde 106. It was a pity that 1,2-addition of 106 could not make the cis-dracunculifoliol directly. Therefore, 107 was oxidized and followed by reduction then the desired compound would be achieved.
In the second part, the substituted ?-iodoketone was applied in microwave heating and proceeds high-speed radical cyclization. Compared to conventional tin-catalyzed procedure, we found significant not only the vinyl-iodo products but also some new result from obviously 1,5-hydrigen shift. In some kinds of examples, we found the cyclization could also possible accomplished in aqueous solution. It is helpful to reduce the damage of earth resulted from organic solvent. Then we also realized that allen-type compounds could cyclized faster than alkynyl-type compounds.

並列關鍵字

axamide-1 ； axisonitrile-1 ； cis-dracunculifoliol ； a-iodoketone ； Radical cyclization ； microwave ； 1,5-hydrigen shift.

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