Asymmetric synthesis of alpha-halo esters

Article abstract of DOI:10.1016/S0040-4039(00)61779-3

The reaction of (R)-Pantolactone with α-halogenated ketenes has been found to proceed with good to excellent diastereoselectivities (de 75 to> 95%). The (R)-Pantolacto chiral auxiliary induced the (S)-configuration at the new chiral center in most cases.