A Practical and User-Friendly Method for the Selenium-Free One-Step Preparation of 1,2-Diketones and their Monoxime Analogs
作者:Georg Rüedi、Matthias A. Oberli、Matthias Nagel、Christophe Weymuth、Hans-Jürgen Hansen
DOI:10.1055/s-2004-832815
日期:——
Treatment of α-methylene ketones with excess sodium nitrite and aqueous HCl in THF at reduced temperatures provides an effective tool for the preparation of a variety of 1,2-diketones. The diastereoselective synthesis of the corresponding (Z)-1,2-dione monoximes could be accomplished under similar conditions, but by using only one equivalent of nitrosatingreagent.
Stereo- and Regioselectivity in Dynamic Gas-Phase Thermoisomerization (DGPTI): Novel Route to α-Campholanic Acid and Derivatives
作者:Georg Rüedi、Matthias Nagel、Hans-Jürgen Hansen
DOI:10.1021/ol034882t
日期:2003.7.1
Dynamic gas-phase thermoisomerization (DGPTI) of (-)-2-phenylisoborneols effects stereo- and regioselective ring opening under formation of (+)-trans-alpha-campholanic acid derivatives. Similarly, (-)-alpha-2-phenylfenchol underwent under DGPTI conditions ring opening to H-fencholic acid derivatives. In both cases, DGPTI led to cleavage of the weakest bond in the isomeric bicyclic structures. A reaction mechanism involving a diradical intermediate is supported by a deuterium labeling study.