Asymmetric total synthesis of ( R )-α-cuparenone, ( S )-cuparene and formal synthesis of ( R )-β-cuparenone through Meinwald rearrangement and ring closing metathesis (RCM) reaction
作者:Rajan Kumar、Joydev Halder、Samik Nanda
DOI:10.1016/j.tet.2016.12.072
日期:2017.2
Asymmetricsynthesis of enantiopure cuparenoid sesquiterpenes (R)-α-cuparenone, (S)-cuparene and a formal synthesis of (R)-β-cuparenone was presented in this article. Meinwald rearrangement of an enantiopure trisubstituted 2,3-epoxy alcohol derivative was the key reaction employed to construct the quaternary streocenter in the target molecules. Ring closing metathesis (RCM) reaction was explored in
New Strategy for Forging Contiguous Quaternary Carbon Centers via H2O2-Mediated Ring Contraction
作者:Weiqing Xie、Jiadong Hu、Xin Yu
DOI:10.1055/s-0036-1590979
日期:2017.12
product synthesis. A general protocol that enables stereospecific construction of all stereoisomers of such a moiety remains elusive. In this article, we will discuss the oxidativering contraction of all-substituted cyclic α-formyl ketones mediated by H2O2, which provides a facile access to the stereospecific construction of contiguous quaternary carbon centers.
ketones was facilitated by the action of H2O2 under operationally simple and environmentally benign reaction conditions. The process was highly regioselective and enables stereospecific construction of contiguous quaternary all‐carbon centers from stereodefined all‐substituted all‐cyclic ketones. The asymmetric syntheses of (+)‐cuparene and (+)‐tochuinyl acetate were also successively achieved by taking advantage
在操作简单和环境友好的反应条件下,H 2 O 2的作用促进了环状α-甲酰基酮的氧化环收缩。该过程具有高度的区域选择性,并能够从立体定义的全取代的全环酮立体构筑连续的季碳全碳中心。利用该新方案还成功实现了(+)-cuparene和(+)-tochuinyl乙酸酯的不对称合成。
Photomediated asymmetric synthesis of (–)-cupareneElectronic supplementary information (ESI) available: experimental procedures and data including copies of 1H-NMR and 13C-NMR spectra for all new compounds, and NOESY spectra for compounds 9, 10, 11, 15 and 16. See http://www.rsc.org/suppdata/cc/b3/b300815k/
作者:Richard S. Grainger、Aslam Patel
DOI:10.1039/b300815k
日期:2003.4.16
Generation of a benzylic quaternary stereocentre via the photomediated cyclisation of a chiral α-(aminobutyl)styrene followed by a microwave-assisted Cope elimination has led to a total synthesis of the sesquiterpene (â)-cuparene.
Synthesis of (S)-(−)-β-cuparenone and (S)-(−)-cuparene
作者:Bhasker Reddy Aavula、Qi Cui、Eugene A. Mash
DOI:10.1016/s0957-4166(00)00457-2
日期:2000.12
A short and efficient synthesis of the title compounds is described. (S)-(−)-β-Cuparenone was prepared in 31% yield from p-tolualdehyde and mesityl oxide in eight steps. Absolute stereochemistry was established by means of a diastereoselectivecyclopropanation using (R,R)-hydrobenzoin as a recoverable auxiliary.