The reaction of (R)-Pantolactone with alpha-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.
The reaction of (R)-Pantolactone with alpha-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.