Crystallization-Induced Diastereomer Transformations of Brominated Arylacetic and Arylpyruvic Acids

Enantiopure halogenated carboxylic acid derivatives are valuable building blocks for the synthesis of stereochemically complex and pharmaceutically relevant molecules. We report the crystallization-induced diastereomer transformations (CIDTs) of diastereomeric salt pairs of α-bromo arylacetic and β-bromo arylpyruvic acids. The salts were obtained with high diastereoselectivities via direct filtration of the reaction mixture, and a salt break facilitated recovery of the enantiopure acids and chiral amines in high yields. The former react to produce synthetically useful enantiopure building blocks.