Highly Enantioselective Construction of Fused Pyrrolidine Systems That Contain a Quaternary Stereocenter: Concise Formal Synthesis of (+)‐Conessine

Abstract

No protecting groups were required in a concise and atom-economical synthesis of the optically active tetracyclic pyrrolidine 3 under mild conditions. A highly diastereoselective Pauson–Khand reaction (1→2) was used to construct the compact tetracycle with its quaternary stereocenter. The stereoselectivity of the cycloaddition was affected by the substituent on the propargylic moiety. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2004/z53583_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.