Synthesis of guaipyridine alkaloids (±)-cananodine and (±)-rupestines D and G using an intramolecular Mizoroki-Heck reaction
作者:Patrick M.M. Shelton、Samantha M. Grosslight、Briana J. Mulligan、Hope V. Spargo、Silvana S. Saad、James R. Vyvyan
DOI:10.1016/j.tet.2020.131500
日期:2020.10
rupestine G were synthesized in six steps or less from readily available 3-(allyloxy)-2-(bromomethyl)-6-methylpyridine. Key steps in the synthesis include an enolate alkylation of the aforementioned substituted picolyl bromide and an intramolecular Mizoroki-Heck reaction to form the seven-membered carbocycle of the target compounds.
Synthesis of cananodine by intramolecular epoxide opening
作者:Patrick Shelton、Toby J. Ligon、Jennifer M. Dell (née Meyer)、Loagan Yarbrough、James R. Vyvyan
DOI:10.1016/j.tetlet.2017.07.080
日期:2017.8
is a guaipyridine alkaloid with activity against liver cancer. Cananodine was synthesized using a remarkable intramolecular opening of a trisubstituted epoxide as the key step in construction of the seven-membered carbocycle of the target. The epoxide opening strategy allows all four stereoisomers of cananodine to be prepared.
Enantioselective construction of substituted pyridine and a seven-membered carbocyclic skeleton: biomimetic synthesis of (−)-rupestine D, (−)-guaipyridine, (−)-epiguaipyridine, and (−)-cananodine and their stereoisomers
opening of a trisubstituted epoxide for the formation of a chiral center at C-8; (ii) ring-closing metathesis for the construction of a seven-membered carbocyclic ring; and (iii) biomimetic cyclization of a 1,5-dicarbonyl compound for the construction of a pyridine-fused bicyclic skeleton.