Synthetic studies on natural products containing highly substituted heterocyclic skeletons using ring-opening cyclization of spirocyclopropanes

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07853
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Chemical pharmacy
• Research Institution: University of Toyama
• Principal Investigator: NAMBU Hisanori 富山大学, 大学院医学薬学研究部(薬学), 准教授 (80399956)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 複素環天然物 / スピロシクロプロパン / 環化反応 / 多置換芳香族化合物 / 天然物 / 合成 / インドール / ベンゾフラン

Outline of Final Research Achievements

Ring-opening cyclization of spirocyclopropanes for the construction of a benzofuran skeleton was developed. The reaction of aryl-substituted spirocyclopropanes with acid catalysts proceeded smoothly to provide tetrahydrobenzofuran-4-ones in high yields. However, the reactions of non-substituted and electron-withdrawing group-substituted spirocyclopropanes using acid catalyst did not occur. After considerable experimentation, we found that iodide ion was an effective catalyst for these reactions.
We also developed the divergent synthesis of highly substituted indoles via the common synthetic intermediates tetrahydroindol-4-ones, which was prepared by the ring-opening cyclization of spirocyclopropanes with amines.

Free Research Field

有機合成化学