The copper-catalyzed conjugate addition-cycloacylation reaction of zinc homoenolatee with acetylenic esters or acetylenic amides is described. The zinc homoenolate is prepared from [ (ethoxycyclopropy1)oxyltrimethylsilane and zinc chloride in ether. Addition of an acetylenic amide or ester provides 2-carboxamidoor 2-carboalkoxy-3-alkylcyclopent-2-en-l-ones ingood to excellent yields. The reacti...

the adducts produced in the reaction between trialkyl phosphites and acetylenic esters were trapped by hydantoins to produce highly functionalized dialkyl 2-(2,5-dioxo-4,4-diphenylimidazolidin-1-yl) succinate in good yields.

reaction of dialkyl acetylenedicarboxylates 1a-c andpyrrole derivatives 2a-e in the presence of triphenylphosphite (tpp) was investigated and the effect of the pyrrole substitution was established. diastereoselectivity is observed with pyrroles, 2a,b, yieldingphosphonate ester derivatives 3a-f and 4,and their relative configuration is determined by 1h/13c and 31p nmr and confirmed by single x-r...

The adducts produced in the reaction between trialkyl phosphites and acetylenic esters were trapped by hydantoins to produce highly functionalized dialkyl 2-(2,5-dioxo-4,4-diphenylimidazolidin-1-yl) succinate in good yields.

Methyl esters of polyunsaturated fatty acids labeled with tritium were prepared by partial stereoselective reduction of the corresponding acetylenic esters with tritiated disiamylborane, followed by protonolysis with tritiated acetic acid. The labeling was strictly specific, and the tritium atoms were located only at the carbon atoms forming the unsaturated bond(s). Synthesis of some tritiated ...

two-component reaction of 2-aminobenzophenones with acetylenic esters in the presence of γ-al2o3 and cu/zno as suitable heterogeneous catalysts has been studied. nano γ-al2o3 and cu/zno showed high activities when used as surface catalysts for the synthesis of quinoline derivatives. after completion of the reaction, the catalyst was recovered and reused several times under the same reaction con...

Two-component reaction of 2-aminobenzophenones with acetylenic esters in the presence of γ-Al2O3 and Cu/ZnO as suitable heterogeneous catalysts has been studied. Nano γ-Al2O3 and Cu/ZnO showed high activities when used as surface catalysts for the synthesis of quinoline derivatives. After completion of the reaction, the catalyst was ...

protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and acetylenic esters, by nh-acids such as azathioprine, imidazole or theophylline leads to the formation of vinyltriphenylphosphonium salts, which undergo a michael addition reaction with a conjugate base to produce phosphorus ylides. silica nanoparticles (silica nps were prepared by therm...

The enantioselective synthesis of Anomala osakana pheromone and Janus integer pheromone has been achieved without using any protecting groups. The synthesis involved using an asymmetric alkynylation to obtain gamma-hydroxy-alpha,beta-acetylenic esters with high ee (84%) and yields ( approximately 80%), followed by selective hydrogenation and lactonization in high overall yields (87% and 89%).