(E)-β-borylstyrene in the Diels-Alder reaction with 3,5-dibromo-2-pyrone for the syntheses of (±)-1-epi-pancratistatin and (±)- pancratistatin.

New synthetic routes to (±)-1-epi-pancratistatin and (±)-pancratistatin were devised using (E)-β-borylstyrene as a dienophile for the key Diels-Alder reaction with 3,5-dibromo-2-pyrone. The boronate in the cycloadduct was oxidized to provide the pivotal C1-hydroxyl group of the titled compounds.