Total Synthesis of Gelsemoxonine

The first total synthesis of gelsemoxonine (1) has been accomplished. Divinylcyclopropane-cycloheptadiene rearrangement of the highly functionalized substrate was successfully applied to assemble the spiro-quaternary carbon center connected to the bicyclic seven membered core structure. A one-pot isomerization reaction of the alpha,beta-unsaturated aldehyde to the saturated ester via the TMSCN DBU reagent combination allowed a facile diastereoselective introduction. of the latent nitrogen functionality of the unique azetidine moiety.