Electrochemically Driven Dearomative Spirocyclization of Anisole-Based Cyclopropanols: Total Synthesis of Anhydro-β-rotunol.

An eco-friendly electrochemical oxidative dearomatization of anisole-based cyclopropyl alcohols has been developed for synthesizing spiro[4.5]diketones. The reaction involves the simultaneous C-C bond cleavage of cyclopropyl alcohols and spirocyclization with anisole under electrochemical conditions, eliminating the need for metal catalysts or additional oxidants. Via the efficient construction of five- and six-membered rings, this approach enables the synthesis of structurally diverse spirocyclic diketones with a broad substrate scope and compatibility with various functional groups. Notably, the method has been applied to the synthesis of anhydro-β-rotunol, a compound isolated from infected potato tubers and tobacco leaves.