The ubiquitous structure of δ-lactones makes the development of new methods for their enantioselective and stereoselective synthesis an important ongoing challenge. The intermolecular dynamic kinetic resolution (DKR) of β-halo-α-ketoesters cooperatively catalyzed by an N-heterocyclic carbene and a Lewis acid generates two contiguous stereocenters with remarkable diastereoselectivity through an oxidation/lactonization sequence.
Keywords: N-heterocyclic carbene; annulation; dynamic kinetic resolution; lactones; oxidative addition.
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