Synthesis and Reactions of 3-(Nosyloxy)-2-keto Esters
摘要:
A series of 3-(nosyloxy)-2-keto esters 7a-j were prepared from the corresponding cr-keto esters by conversion to the trimethylsilyl enol ether and reaction with p-nitrobenzenesulfonyl peroxide. Conversion of these materials to 1,2,3-trifunctionalized compounds is described, and comparison of their properties with isomeric 2-(nosyloxy)-3-keto esters is discussed.
Synthesis of Rigid Receptors Based on Triphenylene Ketals
作者:Matthias C. Schopohl、Andreas Faust、Daniela Mirk、Roland Fröhlich、Olga Kataeva、Siegfried R. Waldvogel
DOI:10.1002/ejoc.200500108
日期:2005.7
The synthesis of rigid receptors based on triphenylene ketals, including some improved procedures, is described in detail. Since chemical transformations are strongly influenced by the rigid character and steric bulkiness of the receptors, the construction of a subunit allowing quicker synthetic development is also reported. The preparation of these receptor structures involves an oxidative trimerization
A Novel Three-Component [3+2] Cycloannulation Process for the Rapid and Highly Stereoselective Synthesis of Pyrrolobenzoxazoles
作者:Michael Boomhoff、Christoph Schneider
DOI:10.1002/chem.201200405
日期:2012.4.2
Four new σ bonds and two chiral centers are formed in a novel three‐component, one‐pot [3+2] cycloannulationprocess, which gives pyrrolobenzoxazoles directly in good yields and with excellent diastereoselectivity (see scheme, TMS=trimethylsilyl). The products could be converted into proline derivatives with full stereochemical control. A chiral scandium complex catalyzed the formation of the products