(S)-4-(tert-Butoxycarbonyl)-3-methylmorpholine-3-carboxylic acid is primarily utilized in the field of organic synthesis, particularly in the preparation of complex molecules. It serves as a key intermediate in the development of pharmaceuticals, especially in the synthesis of active pharmaceutical ingredients (APIs) that require specific stereochemistry. The compound is often employed in the construction of morpholine derivatives, which are valuable in drug discovery due to their presence in various biologically active compounds. Additionally, its tert-butoxycarbonyl (Boc) protecting group makes it a useful reagent in peptide synthesis, where it helps in the controlled assembly of amino acids. This chemical is also explored in the design of ligands for asymmetric catalysis, contributing to the production of enantiomerically pure substances.