Asymmetric synthesis of tetra-substituted cyclopropanes and its application to highly selective organic synthesis

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05420
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Organic chemistry
• Research Institution: Shinshu University
• Principal Investigator: Nishii Yoshinori 信州大学, 学術研究院繊維学系, 准教授 (40332259)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: シクロプロパン / 不斉合成 / リグナン / 天然物 / 炭素炭素結合切断 / 開環 / 環化 / 生物活性物質

Outline of Final Research Achievements

We investigated ring-opening cyclization, homo-Nazarov cyclization, oxy-homo-Michael reaction, 1,5-addition and reductive ring-opening reaction of enantioenriched donor-acceptor cyclopropanes. In addition, a couple of asymmetric total synthesis of bioactive lignans using a couple of these reactions as key steps. Namely, we achieved the asymmetric total synthesis of tupichilignan A using the highly stereoselective Cu-catalyzed oxy-homo-Michael (OHM) addition of alcohols into bicyclic donor-acceptor cyclopropanes as a key step. Moreover, Cu-catalyzed 1,5-addtion of Grignard reagent instead of alcohols into the enantioenriched donor-acceptor cyclopropanes also proceeded with high regio- and stereoselectivity. In addition, we reported the reductive ring-opening of D-A cyclopropanes and its application for the total synthesis of yatein. Beside the intermolecular reaction, we verify the reaction mechanism of ring-opening cyclization and homo-Nazarov cyclization of D-A cyclopropanes.

Free Research Field

有機合成化学