Used as a chiral building block in the synthesis of pharmaceuticals, particularly in the development of active pharmaceutical ingredients (APIs) where stereochemistry plays a critical role. Its morpholine ring and carboxylic acid functionality make it suitable for incorporation into biologically active molecules, including antiviral and anticancer agents. Commonly employed in medicinal chemistry for structure-activity relationship (SAR) studies due to its ability to influence solubility, metabolic stability, and target binding. Also utilized in the preparation of peptidomimetics and enzyme inhibitors where the (S)-configuration is essential for activity.