Niaviolides, New Macrocyclic Sesquiterpenes Secreted by Males of the African Butterfly <i>Amauris niavius</i>

Abstract

Abstract The abdominal androconial organs (“hairpencils”) of the African butterfly Amauris niavius (Danainae) emit a complex scent bouquet consisting of previously described aromatic compounds, terpenoids, fatty acids, and hydrocarbons. This work reports the identification of two major sesquiterpenes, each possessing a unique 13‐membered macrolide ring, originating from an α,ψ‐oxidation pattern of the sesquiterpene backbone. To the best of our knowledge, sesquiterpene macrolides have not been found before in nature. The structure elucidation of the two compounds, which we propose to call niaviolide ( 3 ) and epoxyniaviolide ( 4 ), by NMR and GC/MS experiments is presented, together with their subsequent synthesis. Finally, the absolute configuration of natural 4 was determined to be ( S , S ) by stereoselective synthesis and chiral gas chromatography. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2003)