Total synthesis of (±)-α-Lycorane via Diels – Alder Reaction of 3,5-Dibromo-2-pyrone

Abstract

We have launched a new efficient synthetic route to (±)-α-Lycorane by utilizing the Diels-Alder reaction of 3,5-dibromo-2-pyrone. In summary, We have launched a new efficient synthetic route to (±)-α-Lycorane by utilizing the Diels-Alder reaction of 3,5-dibromo-2-pyrone. The endo-cycloadduct of 3,5-dibromo-2-pyrone with styrene-type dienophile provided the pivotal intermediates for the synthesis of the titled natural alkaloids. The key steps are Diels-Alder reaction, Eschenmoser-Claisen rearrangement and Curtius rearrangement. The total yield is 23.2% over 10 steps.