Total Synthesis of Cruentaren A


  • Financial support from the Deutsche Forschungsgemeinschaft (grant Ma 1012/20-1) and the Fonds der Chemischen Industrie is gratefully acknowledged. We thank Frank Lay (Institute of Organic Chemistry) for important model studies. We also thank the research group of Stefan Berger, University of Leipzig, for measuring the HRMS spectra. We also thank Paul Schuler (Institute of Organic Chemistry) for measuring several NMR spectra (600 MHz) of cruentaren A. Skilful assistance by Marcellino Calá and Vaidotas Navickas (Institute of Organic Chemistry) is also acknowledged. A graduate fellowship for V.V.V. from the state Baden-Württemberg (LGFG) is gratefully acknowledged.


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A triple bypass: The triple bond in the macrolactone ring of 2 served as a lock to prevent the unwanted translactonization to the δ-lactone during the formation of the side chain of the macrolide cruentaren A (1). Subsequent cleavage of the methyl ether and the silicon protecting groups (PG) followed by a Lindlar reduction of the two triple bonds completed the synthesis (see scheme).