Asymmetric Total Synthesis of (-)-trans-Blechnic Acid via Rhodium(II)-Catalyzed C-H Insertion and Palladium(II)-Catalyzed C-H Olefination Reactions

作者：Ito Motoki; Namie Ryosuke; Krishnamurthi Janagiraman; Miyamae Hitomi; Takeda Koji; Nambu Hisanori; Hashimoto Shunichi^*

来源：Synlett, 2014, 25(2): 288-292.

DOI：10.1055/s-0033-1340291

• chiral dirhodium(II) catalyst
• C-H insertion
• C-H olefination
• dihydrobenzofuran neolignan
• blechnic acids

An asymmetric total synthesis of (-)-trans-blechnic acid, a dihydrobenzofuran neolignan, has been achieved. The key steps involve an elaboration of the cis-2,3-dihydrobenzofuran core structure by enantio- and diastereoselective intramolecular C-H insertion using dirhodium(II) tetrakis[N-phthaloyl-(R)-tert-leucinate] [Rh-2(R-PTTL)(4)] and a direct coupling of an acrylate unit with the core structure employing Yu's palladium(II)-catalyzed intermolecular C-H olefination.

• 出版日期2014-1-23