Preparation of medium-ring acetylenic lactones utilizing metal-promoted alkyne bending
作者:Neil E. Schore、Samir D. Najdi
DOI:10.1021/jo00232a050
日期:1987.11
Use of metal complexation in the synthesis of medium-ring acetylenic lactones
作者:Samir D. Najdi、Marilyn M. Olmstead、Neil E. Schore
DOI:10.1016/0022-328x(92)83338-i
日期:1992.7
The hexacarbonyldicobalt complexes of several appropriately designed acetylenic lactone precursors have been prepared, and lactones containing Co2(CO)6-complexed triple bonds in seven-, ten-, and eleven-membered rings obtained. The latter were best obtained through a retro-Dieckmann fragmentation of 2-(hydroxybutynyl) derivatives of 1,3-cyclohexanedione. Attempts to extend this reaction to cyclohexanones bearing other anion-stabilizing groups in the 2-position or to 1,3-cyclopentanediones were unsuccessful. Decomplexation afforded the metal-free 11-ring lactone, characterized crystallographically. Treatment of this system with basic reagents led to dimerization. In the case of the smaller rings, cyclization of the complexed acetylenic hydroxyacids under Mukaiyama conditions (2-chloro-N-methylpyridinium iodide, CH2Cl2, reflux) succeeded in modest yields.
Function‐Oriented and Modular (+/−)‐
<i>cis</i>
‐Pseudoguaianolide Synthesis: Discovery of New Nrf2 Activators and NF‐κB Inhibitors
作者:Fabien Emmetiere、Ranjala Ratnayake、Henry A. M. Schares、Katherine F. M. Jones、Emily Bevan–Smith、Hendrik Luesch、Daniel A. Harki、Alexander J. Grenning
DOI:10.1002/chem.202100038
日期:2021.3.22
Described herein is a function‐oriented synthesis route and biological evaluation of pseudoguaianolide analogues. The 10‐step synthetic route developed retains the topological complexity of the natural product, installs functional handles for late‐stage diversification, and forges the key bioactive Michael acceptors early in the synthesis. The analogues were found to be low‐micromolar Nrf2 activators