Structure of Elemanschkuhriolide. Melampolides as Possible Biogenetic Precursors of C14α,H5β Elemanolides

Article abstract of DOI:10.1021/jo00190a027

The structure and stereochemistry of the new C₁₄α,H₅β elemanolide, elemanschkuhriolide (8) from Schkuhria schkuhrioides is reported.Schkuhriolide (2), isolated from the same plant source, was transformed into 8 via a Cope rearrangement and this is the first <3,3> sigmatropic reaction of a melampolide with a lactone ring closed at C(8) and cis annelated.The biogenesis of C₁₄α,H₅β elemanolides from melampolides is discussed.