Reactivity of Lithium β-Ketocarboxylates: The Role of Lithium Salts
作者:Mateo Berton、Rossella Mello、Paul G. Williard、María Elena González-Núñez
DOI:10.1021/jacs.7b08450
日期:2017.12.6
Lithium β-ketocarboxylates 1(COOLi), prepared by the reaction of lithiumenolates 2(Li+) with carbon dioxide, readily undergo decarboxylative disproportionation in THF solution unless in the presence of lithium salts, in which case they are indefinitely stable at room temperature in inert atmosphere. The availability of stable THF solutions of lithium β-ketocarboxylates 1(COOLi) in the absence of carbon
Intramolecular addition of aryl radicals to vinylogous urethanes: studies toward preparation of the oxindole portion of gelsemine
作者:David J. Hart、Shung C. Wu
DOI:10.1016/s0040-4039(00)79873-x
日期:1991.8
Free radical cyclization of vinylogous urethanes 5 and 12 gave spiro oxindoles 6 and 13 + 14, in 95% and 84% yields, respectively. Cyclization of projected gelsemine intermediate 19 resulted in the formation of oxindole 22 via a cyclization, 1,4-hydrogen atom transfer, reduction sequence.