Biomimetic Total Synthesis of (±)‐Verrubenzospirolactone

A five‐step total synthesis of (±)‐verrubenzospirolactone has been achieved using a biomimetic, intramolecular Diels–Alder reaction of a 2 H ‐chromene to form two rings and four stereocenters in the final step. This Diels–Alder reaction occurs spontaneously at 30 °C “on‐water”, and thus suggests that it is likely to be non‐enzymatic in nature. The structure of (±)‐verrubenzospirolactone was also used to inspire a quadruple cascade reaction to generate seven stereocenters, four rings, three C−C bonds, and two C−O bonds in one step.