Used in peptide synthesis as a protected intermediate, particularly in the preparation of tyrosine-containing peptides. The Boc group protects the amino terminus, while the methyl ester (OL) masks the carboxylic acid, allowing selective coupling at other reactive sites. Commonly applied in solid-phase and solution-phase synthesis of bioactive peptides, including hormone analogs and enzyme substrates. Also utilized in medicinal chemistry for developing protein inhibitors and in research settings for studying peptide structure-activity relationships.