A novel phosphine-catalyzed highly diastereoselective [3+2] cycloaddition of isatin derived α,β-unsaturated ketones with α-allenic ester has been developed.

a,b-Unsaturated carbonyl compounds are basic building blocks in organic synthesis. Lewis acid catalysts bearing chiral ligands have traditionally been used for the asymmetric catalytic activation of this class of molecules as Michael acceptors. Indeed, Lewis acid catalysis continues to be a powerful approach in which innovative solutions are still emerging. Representative examples of chiral Lew...

The present invention provides a process for the synthesis of an α,β-unsaturated ester from a mono-olefinester using Fe(CO).sub.5.

The Johnson-Claisen rearrangement of D-gluco and L-ido-derived allylic orthoesters afforded gamma,delta-unsaturated ester that on ester reduction, epoxidation, regioselective oxirane opening by sodium azide and hydrogenation led to sugar amino alcohols--immediate precursors for 1-deoxy-homonojirimycin 3a,b, and polyhydroxylated homoazepanes 4a,b. Our synthetic approach and glycosidase inhibitor...

Oxygen, a key nutrient in alcoholic fermentation, is rapidly depleted during this process. Several pathways of oxygen utilization have been reported in the yeast Saccharomyces cerevisiae during alcoholic fermentation, namely synthesis of unsaturated fatty acid, sterols and heme, and the mitochondrial electron transport chain. However, the interaction between these pathways has not been investig...

Bifunctional phosphinothiourea catalysts have been developed successfully for the highly regio- and enantioselective γ-hydroamination of allenyl and propargyl esters with N-methoxy carbamate nucleophiles to yield α,β-unsaturated γ-amino acid ester products. In the case of propargyl ester substrates, the reaction proceeds through reversible phosphinothiourea-catalyzed isomerization to the corres...

A new enantioselective total synthesis of pachastrissamine (jaspine B) was achieved from a known alpha,beta-unsaturated aldehyde by utilizing Córdova's asymmetric epoxidation as the chirality-inducing step. The 2,3-cis stereochemistry of pachastrissamine was established via intramolecular epoxide ring opening of a gamma,delta-epoxy-alpha,beta-unsaturated ester intermediate coupled with oxy-Mich...

Sequential Wolff rearrangement of α-diazo-β-ketoesters followed by trapping of the ketene intermediates with enol ethers generated a variety of γ,δ-unsaturated β-ketoesters. This method involves a novel thermal cascade reaction and allows the synthesis of γ,δ-unsaturated β-ketoesters with trans-stereochemistry under catalyst-free conditions. The synthesized compounds were further transformed in...

In this research, a method was used to increase the brittleness of unsaturated polyester polymer by mixing it with vinyl ester. The choice ester toughness is because easy form and material has wide applications in engineering. However, several weaknesses, namely, very stiff, brittle, unable withstand cracking loads breaks easily due impact. Polyester rigid nature cross-chain links that are tigh...