L-Threonine tert-Butyl Ester Hydrochloride is primarily used in the synthesis of peptides and proteins, serving as a protected form of L-threonine. It is particularly valuable in solid-phase peptide synthesis (SPPS), where the tert-butyl group acts as a protective group for the hydroxyl side chain, preventing unwanted reactions during the peptide assembly process. This compound ensures the selective deprotection and coupling of amino acids, enabling the efficient production of complex peptides. Additionally, it is employed in the preparation of modified peptides and peptidomimetics for pharmaceutical research, aiding in the development of therapeutic agents targeting various diseases. Its stability and compatibility with common peptide synthesis protocols make it a reliable reagent in organic and medicinal chemistry.