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  • 學位論文

Synthetic studies toward the Left Segment of Solanoeclepin A

指導教授 : 磯部 稔
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摘要


天然物Solanoeclepin A 1,具有刺激馬鈴薯中的囊腫線蟲提早孵化的功能,可運用在農業病蟲害防治上。本論文專注在Solanoeclepin A 中左半片段四環骨架152 之建構。包含7-氧基雙環[2.2.1]庚烷、六、七員環和六個不對稱中心之架構。 我們實驗室先前利用(S)-(-)-4-甲氧基-α-甲苄胺為掌性輔助基試劑,經由分子內的Diels-Alder 反應建構出左半7-氧基雙環[2.2.1]庚烷的基本骨架。 合成途徑以化合物106 經由七步反應後可得到烯炔化合140。加成產物140 與 Co2(CO)8 進行錯合反應後獲得環化前驅物144,隨後於二甲基氯化鋁催化下進行分子內普林斯羰基-ene 環化反應可得到產物148a,最後脫去鈷試劑後建構出四環之骨架152。

關鍵字

天然物 全合成

並列摘要


Solanoeclepin A 1 shows significant hatch-stimulating activity for the potato cyst nematodes. In this thesis, we focused on the synthesis of the tetracyclic diene 152, including 7-oxabicyclo[2.2.1]heptane moiety, six- and seven-membered ring bearing six chiral centers. The 7-oxabicyclo[2.2.1]heptane moiety was obtained via a diastereoselective IMDA (intramolecular Diels-Alder reaction) strategy by using a chiral auxiliary (S)-(-)-4-methoxy-α-methylbenzylamine as the source for this synthesis. This synthesis started from 106 and it was converted to enyne 140 in seven steps. After complexation of acetylene 140 with Co2(CO)8, the cyclization precursor 144 was obtained and subjected to intramolecular Prins-Carbonyl-Ene cyclization via Me2AlCl catalysis to yield stereoselective cyclic product 148a. Next, removal of cobalt afforded the tetracyclic diene 152 framework.

並列關鍵字

natural products total synthesis

參考文獻


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