Total Synthesis of (±)‐trans‐Dihydronarciclasine through a Highly endo‐Selective Diels–Alder Cycloaddition of 3,5‐Dibromo‐2‐pyrone

All essential functional groups in the natural product (±)-trans-dihydronarciclasine (1) were introduced with the correct relative configuration in a highly endo-selective Diels–Alder cycloaddition of 3,5-dibromo-2-pyrone with a styrene dienophile (see scheme). The total synthesis of 1 from these starting materials was completed in 11 steps and 15.8 % overall yield.