A Chemoenzymatic Total Synthesis of the Protoilludane Aryl Ester (+)-Armillarivin

The title natural product, <b>1</b>, has been synthesized in 20 steps from the enantiomerically pure <i>cis</i>-1,2-dihydrocatechol <b>2</b>, itself obtained through the whole-cell biotransformation of toluene. The pivotal steps in the reaction sequence involve a Diels–Alder cycloaddition reaction between diene <b>2</b> and cyclopentenone (<b>3</b>) and the photochemically promoted 1,3-acyl rearrangement of the bicyclo[2.2.2]oct-4-en-1-one <b>20</b> derived from the cycloadduct <b>4