Regiodivergent Synthesis of ortho‐ and para‐Cannabinoquinones

Abstract

Spurred by the remarkable biological profile of cannabinoquinoids, we have systematically investigated the periodinane oxidation of their resorcinolic precursors, discovering that the regiochemistry of oxidation, a critical maneuver for bioactivity, depends not only on the nature of the oxidant (λ3‐ vs. λ5‐iodanes), but also on post‐oxidative prototropic‐ and valence tautomeric equilibria that isomerize ortho‐quinones to para‐quinones. By complementary selection of the periodinane oxidant and by freezing prototropic equilibration with O‐methylation, isomeric ortho‐ and para‐quinones could be obtained from mono‐ and diphenolic cannabinoids, setting the stage for the exploration of novel areas of the biological space, and establishing a blueprint for the extension of this strategy to other classes of bioactive alkylresorcinols.