Tong J, Xia T, Wang B. Total Synthesis of (±)-11-
O-Debenzoyltashironin via Palladium-Catalyzed 5-
endo Ene-yne Cyclization Enabled
trans-5-6 Ring Fusion.
Org Lett 2020;
22:2730-2734. [PMID:
32189505 DOI:
10.1021/acs.orglett.0c00689]
[Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Illicium sesquiterpenes are a synthetically fascinating family of polycyclic natural products owing to their diversified pharmacological activities and structural complexity. Our cumulative efforts on developing a universal reductive coupling strategy toward stereoselective assembly of illicium sesquiterpenes recently resulted in a total synthesis of 11-O-debenzoyltashironin, a rare illicium sesquiterpene with a unique allo-cedrane carbon skeleton exhibiting prominent neurotropic activity, with complete stereochemical control. Our key tactics involved an unprecedented Pd(II)-catalyzed 5-endo ene-yne cyclization that directly allowed strained trans-5-6 ring fusion and a late-stage transannular McMurry coupling that furnished the compacted tetracyclic carbon skeleton rapidly.
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