RESUMO
Oxidative degradation and rearrangement of polycyclic polyprenylated acylphloroglucinols (PPAPs) has created diverse families of unique natural products that are attractive targets for biomimetic synthesis. Herein, we report a racemic synthesis of hyperibrin A and its oxidative radical cyclization to give yezo'otogirin C, followed by epoxidation and House-Meinwald rearrangement to give hypermogin D. We also investigated the biomimetic synthesis of norascyronone A via a similar radical cyclization pathway, with unexpected results that give insight into its biosynthesis.
Assuntos
Produtos Biológicos , Materiais Biomiméticos , Floroglucinol , Terpenos , Produtos Biológicos/síntese química , Produtos Biológicos/química , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/química , Estrutura Molecular , Floroglucinol/síntese química , Floroglucinol/química , Terpenos/síntese química , Terpenos/químicaRESUMO
The first total synthesis of bruceol has been achieved using a biomimetic cascade cyclization initiated by a stereoselective Jacobsen-Katsuki epoxidation (and kinetic resolution) of racemic protobruceol-I. A bacterial cytochrome P450 monooxygenase was also found to catalyze the conversion of protobruceol-I into bruceol. The first full analysis of the NMR data of natural bruceol suggested that "isobruceol" was a previously unrecognized natural product also isolated from Philotheca brucei. This was confirmed by the re-isolation, synthesis, and X-ray analysis of isobruceol. In total, eight stereoisomers and structural isomers of bruceol have been synthesized in a highly divergent approach.