THE MICHAEL-TYPE REACTION OF LITHIUM 1-ALKYNYLTRIALKYLBORATES WITH METHYL VINYL KETONE IN THE PRESENCE OF TITANIUM TETRACHLORIDE. A NEW SYNTHESIS OF δ-DIKETONES FROM ORGANOBORANES
作者:Shoji Hara、Kotaro Kishimura、Akira Suzuki
DOI:10.1246/cl.1980.221
日期:1980.3.5
1-Alkynyltrialkylborates readily available from trialkylboranes and lithium acetylides react with methyl vinyl ketone in the presence of titaniumtetrachloride followed by hydrogen peroxide oxidation under neutral conditions to give corresponding δ-diketones.
The chemistry of organoborates. 9. A regiospecific and highly stereoselective construction of trisubstituted αβ-unsaturated ketones, tetrasubstituted αβ-unsaturated ketones and specifically protected 1,3-diketones from alkynyltrialkylborates
作者:Andrew Pelter、M. Eamon Colclough
DOI:10.1016/0040-4020(94)00953-r
日期:1995.1
fashion such that the dioxolanium group and the migrating group are on the same side of the new alkene intermediate. Hydrolysis of the intermediate yields Z-trisubstituted αβ-unsaturatedketones in which all three substituents have different origins and can be independently varied. Oxidation of the intermediates gives β-ketoacetals, which are regiospecifically protected 1,3-diketones. If the initial intermediates
Reactions of trialkylalkynylborates with 2-alkyl-1,3-dioxalan-2-ylium fluorosulphonates. Versatile direct routes to -αβ-unsaturated ketones, specifically protected 1,3-diketones and other ketonic species.