Construction of Eight-Membered Ether Rings by Olefin Geometry-Dependent Internal Alkylation: First Asymmetric Total Syntheses of (+)-3-(<i>E</i>)- and (+)-3-(<i>Z</i>)-Pinnatifidenyne
作者:Hyoungsu Kim、Won Jun Choi、Jaeyoon Jung、Sanghee Kim、Deukjoon Kim
DOI:10.1021/ja035538u
日期:2003.8.1
The first and highly stereoselective asymmetric total syntheses of eight-membered ring ether marine natural products (+)-3-(E)-pinnatifidenyne and (+)-3-(Z)-pinnatifidenyne have been accomplished. Notable features of our syntheses include a novel and efficient construction of oxocene 5 by a highlystereo- and regioselective internal alkylation and direct ketone synthesis of ketone 16 from the alpha-alkyloxy
The asymmetric totalsynthesis of the marine natural product (+)-(3E)-pinnatifidenyne was accomplished. The key features of the synthesis involve the construction of an eight-membered cyclic ether by the abnormally regioselective Pd(0)-catalyzed cyclization, the installation of a double bond in the oxocene skeleton by sequential in situ deconjugative isomerization, and the efficient introduction of