Photooxygenation of a Microbial Arene Oxidation Product and Regioselective Kornblum-DeLaMare Rearrangement: Total Synthesis of Zeylenols and Zeylenones

We report the enantioselective total syntheses of zeylenol (+)‐1, as well as its congeners (−)‐7 and 16, and of 3‐O‐debenzoylzeylenone 28. To this end, a new variant of the Kornblum–DeLaMare rearrangement, which utilises neighbouring‐group participation to impart regioselectivity, has been developed. The approach employs photooxygenation of building blocks derived from a microbial arene oxidation product. New light on a Korny rearrangement: Biooxidation of benzoic acid with R. eutrophus B9 gives a dearomatised diene diol acid that allows concise access to the zeylenol and zeylenone family of polyoxygenated cyclohexene natural products. The synthesis employs diene photooxygenation and a new regioselective variant of the Kornblum–DeLaMare endoperoxide fragmentation has been developed (see scheme).