RDC-Based Determination of the Relative Configuration of the Fungicidal Cyclopentenone 4,6-Diacetylhygrophorone A12
journal contributionposted on 24.05.2013, 00:00 by Volker Schmidts, Maic Fredersdorf, Tilo Lübken, Andrea Porzel, Norbert Arnold, Ludger Wessjohann, Christina M. Thiele
The hygrophorones, a class of cyclopentenones isolated from fruiting bodies of the genus Hygrophorus (basidiomycetes), show promising antifungal activity. While the constitution of 4,6-diacetylhygrophorone A12 (3) and the relative configuration of the stereogenic centers in the cyclopentenone ring were elucidated using standard NMR and MS techniques, the relative configuration of the exocyclic stereogenic center could not be assigned. By introducing a sample of 3 into an alignment medium and measuring anisotropic NMR parameters, namely, residual dipolar couplings, we were able to unambiguously determine the relative configuration of all three stereogenic centers in 4,6-diacetylhygrophorone A12 simultaneously by fitting several structure proposals to the experimental data.