Palladium-Catalyzed Asymmetric Allylic Alkylation of Enolates

Significance

The first example of a palladium-catalyzed highly enantioselective synthesis of α-tertiary hydroxyaldehydes is described using allylic alkylation of siloxy enol carbonates. The reaction proceeds under mild conditions and the substrates can be readily made from α-halo or α-hydroxy ketones. The scope is also broad, encompassing various protecting groups and substituents on the enol ether with excellent yields and enantio­selectivities. The synthetic utility of the methodology is demonstrated by converting one product into a key precursor for the synthesis of the anticholinergic drug (S)-oxybutynin.