The title reaction in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) affords alkylative coupling products in good to excellent yields in 1,2-dichloroethane at room temperature. This coupling reaction under C(sp2)–O cleavage proceeds stereospecifically. The reaction does not affect a coexisting vinyl sulfide group. This feature enables 1,2- and 1,3-carbonyl transposition
double bond migration, hydrogenation of which leads to the products. For the carvomenthene epoxides the results are similar to those found in the 4-t-butyl series with competition between cisaddition and trans addition of hydrogen. The presence of the isopropenyl group leads to slower reactionrates in comparison with t-butyl analogues.
Keto carbonyl 1,2- and 1,3-transpositions with and without alkylation of the substrate are described together with ketone synthesis from thiocarboxylic S-ester.
The conjugateaddition of organolithium reagent to α, β-unsaturatedketone has been accomplished with methylaluminum bis(2, 6-di-tert-butyl-4-alkylphenoxide) (MAD and MAT). Here combination of alkyllithium and MAD (or MAT) constitutes an amphiphilic system that allows to exhibit unusual selectivity in the alkylation of enones with alkyllithium.