Formation of a reasonably stabilized trichloromethyl anion by the reaction of chloroform with electrogenerated base, and its 1,4-addition to α,β-unsaturated carbonyl compounds
A reasonably stabilized trichloromethylanion (TCMA) was formed by the reaction of chloroform with an electrogenerated base prepared by the electroreduction of 2-pyrrolidone, and the addition of this TCMA to α,β-unsaturated esters gave the corresponding β-trichloromethyl esters in good yields.
Selective syntheses for some 1-halogeno-2-alkyl-cis-1,2-cyclopropanedicarboxylic esters were studied. In a ring formation between α-halogenoacetic and α-propylacrylic esters, lithium hydride was a much better condensing agent than sodium hydride for the selective syntheses of cyclopropanedicarboxylic ester possessing two different alcohol residues. A greater reactivity was found at the ester group
Formation of polysubstituted chlorocyclopropanes from electrophilic olefins and activated trichloromethyl compounds
作者:Sylvain Oudeyer、Eric Léonel、Jean Paul Paugam、Christine Sulpice-Gaillet、Jean-Yves Nédélec
DOI:10.1016/j.tet.2005.11.001
日期:2006.2
Chlorocyclopropanes and bicyclic chlorocyclopropanes are prepared in non basic conditions by electroreductive or Mg-promoted Barbier activation of PhCCl3 or Cl3CCO2Me in the presence of acyclic or cyclic α,β-unsaturated carbonyl compounds.