the Darzens glycidic ester synthesis for converting unsaturated ketones or aldehydes into the homologated β,γ- or α,β-unsaturatedaldehydes employing sulfur ylides is described. The carbonyl group is converted into the unsaturated oxirane which is then rearranged to the new aldehyde. High yields of isomerically pure aldehydes are available by this method and the process is of practical importance in
N-Vinylpyridinium tetrafluoroborate salts as reagents for the stereoselective and regioselective synthesis of symmetrical (2E,4E)-1,6-dioxo-2,4-dienes
作者:Ge Gao、Neil Brown、Machiko Minatoya、Keith R. Buszek
DOI:10.1016/j.tetlet.2008.08.076
日期:2008.11
in Pd(0)-catalyzed Suzuki cross-couplingreactions with aryl and vinyl boronic acids. We now report that these crystalline, air-stable, and non-hygroscopic salts are also useful reagents for the synthesis of symmetrical (2E,4E)-1,6-dioxo-2,4-dienes (diene diones), which in turn are valuable starting materials for the synthesis of various five-membered heterocycles. The optimization of reaction conditions
Über einige neue Polyen-diketone und Polyen-diketo-carbonsäuren
作者:G. Pictet、P. Karrer
DOI:10.1002/hlca.19540370616
日期:——
Durch Kondensation von Diacetyl mit Monoaldehyd-fumarsäuremethylester und Muconsäure-monoaldehyd-monomethylester wurden verschiedene Polyen-diketo-carbonsäureester dargestellt und ihre UV.-Absorptionsspektren verglichen.
<i>N</i>-Vinylpyridinium and -ammonium Tetrafluoroborate Salts: New Electrophilic Coupling Partners for Pd(0)-Catalyzed Suzuki Cross-Coupling Reactions
作者:Keith R. Buszek、Neil Brown
DOI:10.1021/ol063027h
日期:2007.2.1
N-Vinylpyridinium and -trialkylammonium tetrafluoroborate salts represent a new class of electrophilic coupling partner for Pd(0)-catalyzed Suzuki cross-coupling reactions and give very good to excellent yields of products with a wide range of boronic acids. The salts are easily prepared from activated acetylenes and pyridinium or trialkylammonium tetrafluoroborates to form crystalline, air-stable
PREPARATION OF TRANS,TRANS MUCONIC ACID AND TRANS,TRANS MUCONATES
申请人:Frost John W.
公开号:US20100314243A1
公开(公告)日:2010-12-16
The present invention relates to the isomerization of cis,cis and/or cis,trans muconic acid or esters thereof to trans,trans muconic acid or esters thereof and to the esterification of such muconic acids.