Advances in the Total Synthesis of Gelsemine

Gelsemine is a remarkable indole alkaloid isolated from the medicinal plant Gelsemium elegans (Carolina or yellow jasmine) and demonstrates effectiveness in alleviating cognitive impairment, suggesting it could treat Alzheimer's disease. Gelsemine comprises seven adjoining chiral carbon centres and hexacyclic cage structures, making it an oddly difficult synthetic target. The unique structure and potential bio-pharmacological properties of gelsemine have led to the publication of nine interesting total syntheses of gelsemine (including three asymmetric syntheses) in the near past three decades by eight distinguished research groups. Several strategies are brimming with modern concepts of synthesis, such as highly enantioselective organocatalytic Diels–Alder reaction and the biomimetic enol–oxonium cyclization reaction. To better explore the therapeutic effects of gelsemine, this review summarizes the progress in the total synthesis tactics and strategies of the fascinating natural product gelsemine.