A Concise and Versatile Synthesis of Alkaloids from Kopsia tenuis: Total Synthesis of (±)‐Lundurine A and B1. Issue 22 (26th May 2014)

• Record Type: Journal Article
• Authors: Arai, Shigeru; Nakajima, Masaya; Nishida, Atsushi
• Is Part Of: Angewandte Chemie international edition. Volume 53:Issue 22(2014)
• Page Start: 5569
• Page End: 5572
• Publication Date: 2014-05-26
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201400464
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A total synthesis of (±)‐lundurines A and B is described. These natural products have a unique hexacyclic skeleton which includes a cyclopropane‐fused indoline. A stereospecific construction of the pentasubstituted cyclopropane core was achieved, by radical cyclization using SmI₂, with perfect stereoselectivity. Cyclizations to give seven‐ and five‐membered heterocycles, under palladium and ruthenium catalysis, respectively, accomplished the total syntheses. The late‐stage construction of the F ring by ring‐closing metathesis enabled access to the title compounds from a spiroindoline intermediate which is a common structure of other kopsia alkaloids.</p> </abstract>