Efficient synthesis of cephalotaxine- and deoxyharringtonine analogues by a trimethylaluminium-mediated domino reaction
摘要:
The synthesis of cephalotaxine- and cephalotaxine amide analogues 14a-c and 16a-c as well as of the deoxyharringtonine analogues 5a,b was performed employing a trimethylaluminium-mediated domino reaction of 9a-c and 8 to give the spirocyclic compounds 7a-c, which was followed by a palladium catalyzed alpha-arylation. (c) 2007 Published by Elsevier Ltd.
Opening of cyclopropyl ketones with SmI2. Synthesis of spirocyclic and bicyclic ketones by intramolecular trapping of an electrophile
作者:Gary A. Molander、Cristina Alonso-Alija
DOI:10.1016/s0040-4020(97)00499-7
日期:1997.6
A method for the opening of cyclopropyl ketones with samarium(II) iodide followed by the intramolecular trapping of an electrophile is described. This process leads to the obtainment of functionalized spirocyclic, bicyclic, and tricyclic ketones in moderate to good yields.
Asymmetric Synthesis of 1-Tetralones Bearing a Remote Quaternary Stereocenter through Rh-Catalyzed C–C Activation of Cyclopentanones
作者:Shusuke Ochi、Ying Xia、Guangbin Dong
DOI:10.1246/bcsj.20200147
日期:2020.10.15
Herein, we describe the preparation of 1-tetralones bearing a remote quaternary stereocenter in a highly enantioselective manner. A sequence of Pd-catalyzed asymmetric 1,4-addition and Rh-catalyzed...
Asymmetric 1,4-reductions of and 1,4-additions to enoates and related systems
申请人:Massachusetts Institute of Technology
公开号:US06465664B1
公开(公告)日:2002-10-15
One aspect of the present invention relates to methods for the transition-metal-catalyzed asymmetric 1,4-addition of a nucleophile, e.g., hydride, to cyclic and acyclic enoates and enones. In certain embodiments of the methods of the present invention, the transition metal catalyst consists essentially of copper and an asymmetric bidentate bisphosphine ligand.
Amberlyst-15-catalyzed intramolecular SN2′ oxaspirocyclization of secondary allylic alcohols. Application to the total synthesis of spirocyclic ethers theaspirane and theaspirone
1-oxaspiro[5.5]undec-7-ene systems have been prepared by utilizing Amberlyst-15-catalyzed intramolecular SN2′ oxaspirocyclizations of secondary allylicalcohols under mild reaction conditions in quantitative yields. This oxaspirocyclization was applied to the total synthesis of theaspirane and theaspirone from β-ionone in five steps.
各种取代的1-氧杂螺[4.4]非6-烯,1-氧杂螺[4.5] dec-6-烯,6-氧杂螺[4.5] dec-1-烯和1-氧杂螺[5.5] undec-7-通过在温和的反应条件下以定量收率利用仲烯丙基醇的Amberlyst-15催化的分子内S N 2'氧代螺环化反应制备烯键体系。该氧杂螺环化以五个步骤应用于从β-紫罗兰酮的茶皮螺烷和茶皮螺酮的全合成中。