Total Synthesis of Cochlearol B via a Catellani- and Visible Light-Enabled [2+2]-Cycloaddition Approach

A new, twelve-step approach towards the meroterpenoid cochlearol B is reported. This strategy takes advantage of a palladium-catalyzed Catellani reaction of a complex chromenyl triflate and a subsequent visible light-mediated [2+2]-cycloaddition to form the central bicyclo[3.2.0]heptane core of cochlearol B. Notably, careful selection and tuning of the photocycloaddition precursor proved crucial to differentiate between cyclopropanation reactions, [4+2] cycloadditions, and selective [2+2]-photocycloadditions.