Unsaturated malonyl esters underwent Pd-catalyzed intramolecular allylic alkylation to give 4-vinyl-substituted γ-lactones. In contrast to the formerly studied cyclization of malonamides, this reaction could be achieved only with a substrate incorporating a suitably positioned silicon moiety, which directs the ionization toward the desired η 3-allylpalladium complex. The resulting 4-[dimethyl-(2-thienyl) silylvinyl] lactone could be subsequently engaged ...
