Total Synthesis and Absolute Configuration Assignment of MRSA Active Garcinol and Isogarcinol |
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| Authors: | Dr. Cecilia Socolsky Prof. Dr. Bernd Plietker |
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| Affiliation: | 1. INQUINOA‐CONICET, Ayacucho 471, 4000 Tucumán (Argentina);2. Institut für Organische Chemie, Universit?t Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart (Germany) |
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| Abstract: | A short total synthesis of (±)‐garcinol and (±)‐isogarcinol, two endo‐type B PPAPs with reported activity against methiciline resistant Staphylococcus aureus (MRSA), is presented. The separation of framework‐constructing from framework‐decorating steps and the application of two highly regio‐ and stereoselective Pd‐catalysed allylations, that is, the Pd‐catalysed decarboxylative Tsuji–Trost allylation and the diastereoselective Pd‐catalysed allyl–allyl cross‐coupling, are key elements that allowed the total synthesis to be accomplished within 13 steps starting from acetylacetone. After separation of the enantiomers the absolute configurations of the four natural products (i.e., (?)‐garcinol, (+)‐guttiferone E (i.e., ent‐garcinol), (?)‐isogarcinol, and (+)‐isoxanthochymol (i.e., ent‐isogarcinol)) were assigned based on ECD spectroscopy. |
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| Keywords: | allylation antibiotics catalysis cross‐coupling natural products |
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