Scope and applications of second generation palladium-catalyzed cycloalkenylation. Stereoselective total syntheses of isoiridomyrmecin, isodihydronepetalactone, and α-skytanthine
作者:Kazutaka Takeda、Masahiro Toyota
DOI:10.1016/j.tet.2011.08.078
日期:2011.12
Functionalized bicyclo[3.2.1]octanes, -oxabicyclo-[4.3.0]nonanes, 3-azabicyclo[3.3.0]octanes, and 3-azabicyclo[4.3.0]nonanes were easily synthesized via a second generation palladium-catalyzed cycloalkenylation. Isoiridomyrmecin and isodihydronepetalactone, both of which feature a 3-oxabicyclo[4.3.0]nonane subunit, were stereoselectively synthesized via a second generation palladium-catalyzed cycloalkenylation
Alkaloid synthesis using 2nd generation palladium-catalyzed cycloalkenylation. Diastereoselective total synthesis of α-skytanthine
作者:Kazutaka Takeda、Masahiro Toyota
DOI:10.1016/j.tetlet.2011.08.162
日期:2011.11
An efficient approach to the synthesis of 3-azabicyclo[3.3.0]octanes and 3-azabicyclo[4.3.0]nonanes by 2nd generation palladium-catalyzed cycloalkenylation is described. Additionally, this reaction is used for the diastereoselective total synthesis of (±)-α-skytanthine.
Cyanomethylenetributylphosphorane was shown to mediate the dehydrocyclization of diols and amino alcohols to give the corresponding 6-membered O- and N-heterocycles in 90% or better yields. Using the reaction as a key step, (+)-alpha-skytanthine, a unique mono terpene alkaloid was synthesized stereoselectively. Copyright (C) 1996 Elsevier Science Ltd