The impressive biological profile of secondary metabolites isolated from strains of Sorangium cellulosum prompted us to initiate synthetic studies on kulkenon, also isolated from Sorangium cellulosum. The synthesis features a syn-selective vinylogous Kobayashi aldol reaction, recently developed by us, and a ring-closing intramolecular Heck reaction as the pivotal transformations. Comparison of the NMR spectra of the authentic and synthetic material revealed that the proposed configuration had to be revised. A combination of molecular modeling and NOE experiments was used to propose the revised configuration, which was confirmed by a new synthesis.
Keywords: Kobayashi aldol reaction; kulkenon; macrolactones; structure elucidation; total synthesis.
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