1391436-01-3Relevant articles and documents
Divergent total synthesis of the lycopodium alkaloids huperzine A, huperzine B, and huperzine U
Ding, Rui,Fu, Jian-Guo,Xu, Guang-Qiang,Sun, Bing-Feng,Lin, Guo-Qiang
, p. 240 - 250 (2014/01/17)
Huperzine A, huperzine B, and huperzine U are congeners isolated from the Chinese herb Huperzia serrata (=Lycopodium serratum) in minuscule amounts. The most efficient total synthesis of huperzine A, the first asymmetric total syntheses of huperzine B, and the first total synthesis of huperzine U have been achieved efficiently in overall yields of 17%, 10%, and 9%, respectively, each spanning 10-13 steps from (R)-pulegone. The featured steps include palladium-catalyzed Buchwald-Hartwig coupling and Heck cyclization reactions and an Ir-catalyzed olefin isomerization reaction. This work has established the absolute configurations of huperzine B and huperzine U and revealed that natural huperzine A, huperzine B, and huperzine U possess the same set of absolute stereochemistries, thus providing support for the potential role of huperzine B and huperzine U in the biosynthesis of huperzine A.
A new approach to the bicyclo[3.3.1]nonane framework of huperzine A-like molecules via palladium-catalyzed intramolecular γ-arylation
Ding, Rui,Lu, Yunyu,Yao, Hequan,Sun, Bingfeng,Lin, Guoqiang
scheme or table, p. 1097 - 1100 (2012/08/28)
In our synthetic studies toward huperzine A, a diastereoselective α′-alkylation of the α-amido-γ-methyl hexenone 4 was realized through a dianion intermediate which significantly enhanced the reactivity. Under the attempted Heck reaction conditions, an unexpected and unprecedented palladium-catalyzed intramolecular γ-arylation of 3 was observed, which generated 18 with bicyclo[3.3.1]nonane framework in satisfactory yield.
