Toward synthesis of Fusicoccin A using ring-expansion strategy

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K13085
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Biomolecular chemistry
• Research Institution: Waseda University
• Principal Investigator: Yamaguchi Junichiro 早稲田大学, 理工学術院, 教授 (00529026)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: フシコクシン / 全合成 / 環変換反応

Outline of Final Research Achievements

We tried to synthesize tricyclic carbon skeleton aiming at the total synthesis of natural product, fusicoccin A Introduction of a side chain of 4 carbon units into benzene and conversion of 4-6-4 carbon skeleton into 5-8-5 condensed ring structure was an extremely novel synthesis plan. That is, it performs continuous ring extension reaction from substituted benzene and converts the 6-membered ring to 8-membered ring. A Buchner reaction was attempted by reacting a substituted benzene obtained in 7 steps from a commercially available compound with a Rh (II) catalyst. As a result, stereoselective cyclopropanation conditions were found and the subsequent 7-membered ring was quantitatively obtained with nearly a single product by divinylcyclopropane rearrangement of the intermediate.

Free Research Field

有機化学、有機合成化学

Academic Significance and Societal Importance of the Research Achievements

生物活性をもつ天然有機化合物などの主骨格を直感的かつ効率的に構築する方法の開発は医農薬の開発段階で利用され、ひいては画期的な製品導出の一助となる。本研究はベンゼンに4炭素ユニットの側鎖を導入し、4-6-4炭素骨格を5-8-5縮環構造に変換するという極めて斬新な合成計画であり、これが一般化されば、創薬現場での利用が期待できる。今回、すべての骨格を合成することはできなかったが、立体選択的に５－７員環を構築する手法を開発することができた。