A Pd-catalyzed asymmetric allylic substitution cascade via an asymmetric desymmetrization for the synthesis of bicyclic dihydrofurans

A Pd-catalyzed asymmetric allylic substitution cascade of allylic meso-dicarbonates with 3-oxo-nitriles has been developed for the synthesis of chiral bicyclic dihydrofurans bearing two vicinal carbon stereocenters. The reaction proceeds via an asymmetric desymmetrization process with the desired products being obtained in high yields and with up to 97% ee. The reaction was performed on a gram-scale and the corresponding bicyclic dihydrofurans could undergo several transformations. The methodology provides an efficient synthetic route to biologically active chiral bicyclic dihydrofurans derivatives.