A chemoenzymatic total synthesis of the protoilludane aryl ester (+)-armillarivin.

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