Total Synthesis Of Lycopodium Alkaloid Lyconadin C

Lycopodium alkaloids are compounds which are structurally related,similar in source and diverse in structure.They were extracted originally and identified in Lycopodium^[1].In1881,Bodeker extracted the first alkaloid---Lycopodine,from Lycopodium complanatum.By 1938,Achmatowicz and Uzieblo also isolated Lycopodine and gave the correct molecular formula and discovered two other new alkaloids.Since the 1940s,a number of Canadian scientists（from WA Ayer’s group）have studied methods for separation,structural analysis,biosynthesis,and chemical synthesis of alkaloids.In the 1980s,Chinese chemists extracted alkaloids with high efficiency,low toxicity and high selectivity to inhibit cholinesterase activity from Huperzia serrata---a herbaceous plant of the genus Heliconia.Huperzine A,which attracted the attention of scientists all over the world.Through the unremitting efforts of natural medicinal chemists,201 species of alkaloids have been isolated and identified from 54 species of Pinus sylvestris.In this thesis,the phenylthiocarbamate-mediated transition metal Pd catalyzed Heck reaction was used as a key reaction to construct the tricyclic skeleton of Lyconadin C,and the synthesis of the natural product was completed by functional group transformation and cyclization.At the same time,this key tricyclic skeleton serves as an important intermediate for the divergent synthesis of four other similar alkaloids Lyconadin A,Lyconadin B,Lyconadin D and Lyconadin E.