Used as a protected amino acid derivative in peptide synthesis, particularly in solid-phase and solution-phase methods. The 1-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl (Dde) group provides temporary protection for the alpha-amino function (N2), while the Boc (tert-butoxycarbonyl) group acts as a side-chain protecting group for the epsilon-amino group (N6) of lysine. This dual protection strategy allows selective deprotection and coupling steps, enabling the controlled assembly of complex peptides. It is especially valuable in the synthesis of biologically active peptides where precise regioselectivity and minimal side reactions are critical. Commonly employed in pharmaceutical research and development for producing peptide-based drug candidates.