Synthesis of (+)-anatoxin-a using enyne metathesis
摘要:
Synthesis of N-tosylanatoxin-a was achieved by metathesis of enyne in cis-substituents on a pyrrolidine derivative. Metathesis reactions of enyne having terminal alkyne using various ruthenium-carbene complexes did not give a good results. However, when the terminal alkyne was protected with a TMS group, the reaction proceeded smoothly using a second-generation ruthenium-carbene complex to give the desired cyclized compound in high yield. Oxymercuration followed by Dess-Martin oxidation afforded N-tosylanatoxin-a. (C) 2004 Elsevier Ltd. All rights reserved.
Further studies on enantioselective synthesis of (+)-anatoxin-a using enyne metathesis: unexpected inversion of chirality via a skeletal rearrangement of 9-azabicyclo[4.2.1]nonene derivative
作者:Tomohiro Tomita、Yoichi Kita、Tsuyoshi Kitamura、Yoshihiro Sato、Miwako Mori
DOI:10.1016/j.tet.2006.05.088
日期:2006.11
is very interesting that (+)-anatoxin-a was synthesized from (S)-pyroglutamic acid via an unusual inversion of chirality, which is rationalized in terms of a skeletal rearrangement of 9-azabicyclo[4.2.1]nonene derivative at the stage of oxymercuration of the diene.
Synthesis of N-tosylanatoxin-a was achieved by metathesis of enyne in cis-substituents on a pyrrolidine derivative. Metathesis reactions of enyne having terminal alkyne using various ruthenium-carbene complexes did not give a good results. However, when the terminal alkyne was protected with a TMS group, the reaction proceeded smoothly using a second-generation ruthenium-carbene complex to give the desired cyclized compound in high yield. Oxymercuration followed by Dess-Martin oxidation afforded N-tosylanatoxin-a. (C) 2004 Elsevier Ltd. All rights reserved.