Methoxycarbonyl-L-tert-leucine is primarily used in the synthesis of peptides and pharmaceutical compounds. Its unique structure, featuring a tert-leucine moiety, enhances the stability and bioavailability of peptide-based drugs. This compound is often employed in the development of protease inhibitors, which are crucial in treating diseases like HIV and hepatitis C. Additionally, it serves as a building block in the production of chiral molecules, aiding in the creation of enantiomerically pure substances for therapeutic applications. Its role in improving the pharmacokinetic properties of drugs makes it valuable in medicinal chemistry and drug design.