Enantioselective synthesis of 4-alkenoic acids via Pd-catalyzed allylic alkylation: stereocontrolled construction of γ and δ-lactones

International audienceAn enantioselective and diastereoselective synthesis of c,d-unsaturated carboxylic acids by palladiumcatalyzed carbon alkylation of bis(trimethylsilyl)ketene acetals with (E)-1,3-diphenylpropenyl acetate was developed. These acids could be efficiently turned into new cor d-halolactones containing multiple stereocenters using a halolactonization protocol. The stereochemistry of these acids was established by X-ray analysis after derivatization to the corresponding amide with (R)-(+)-1-phenylethylamine