Moritz Sinast, Birgit Claasen, Yannick Stöckl, Andreas Greulich, Anna Zens, Angelika Baro, Sabine Laschat
The Journal of organic chemistry 2021 Jun 04The AB ring systems of the clifednamide family, polycyclic tetramate macrolactames (PoTeMs), were prepared by a new, convergent approach employing an intramolecular Diels-Alder (IMDA) reaction. Key steps comprise an organocatalytic Michael addition (>90% enantiomeric excess (ee)), a Mukaiyama aldol reaction for the convergent installation of a diene moiety, and a telescoped hydrozirconation/cross-coupling grafting an enone. The following IMDA furnished a highly functionalized hydrindane (diastereomeric ratio (dr) = 91:1) with the same configuration as the clifednamide scaffold. Advantages of this route are only one required protecting group, 13% overall yield over 9 steps (reduced from previously 17 steps/1.3% overall), and the potential access to the key intermediates in the clifednamide biosynthesis.
Moritz Sinast, Birgit Claasen, Yannick Stöckl, Andreas Greulich, Anna Zens, Angelika Baro, Sabine Laschat. Synthesis of Highly Functionalized Hydrindanes via Sequential Organocatalytic Michael/Mukaiyama Aldol Addition and Telescoped Hydrozirconation/Cross-Coupling as Key Steps: En Route to the AB System of Clifednamides. The Journal of organic chemistry. 2021 Jun 04;86(11):7537-7551
PMID: 34014095
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