Used as a chiral auxiliary in asymmetric synthesis, particularly in the preparation of optically active amino acids and amines. It facilitates stereocontrol during carbon-carbon bond formation, especially in Evans aldol reactions. The scaffold helps direct the facial selectivity of incoming reagents, enabling high enantioselectivity. After serving its purpose, the auxiliary can be cleaved under mild conditions, leaving the desired chiral product intact. Commonly employed in pharmaceutical intermediates synthesis where precise stereochemistry is critical.