Generation of<i>β</i>-Carbonyl Radicals from Cyclopropanol Derivatives by the Oxidation with Manganese(III) 2-Pyridinecarboxylate and Their Reactions with Electron-Rich and -Deficient Olefins
Various β-carbonyl radicals are generated oxidatively from cyclopropanol derivatives by the use of manganese(III) 2-pyridinecarboxylate (Mn(pic)3). These β-carbonyl radicals react with electron-rich olefins such as conjugated silyl enol ethers, a ketene thioacetal, a ketene dithioacetal, and a vinyl ether intermolecularly to give crossed-addition products in good yield. Furthermore, the combined use
作者:Yoshifumi Hachisu、Jeffrey W. Bode、Keisuke Suzuki
DOI:10.1002/adsc.200404092
日期:2004.8
The scope and limitations of intramolecular benzoin-forming reactions of aldehydes and ketones catalyzed by the combination of a thiazoliumsalt and a base are described. After optimization of the reaction conditions, five- and six-membered cyclic acyloins were obtained in good to excellent yields and competing reactions such as intramolecular aldol reactions were suppressed. The analogous closure