Used in solid-phase peptide synthesis to introduce ornithine residues with orthogonal protection. The Dde group protects the side-chain amine, allowing selective deprotection in the presence of other protecting groups like Boc. This enables stepwise assembly of complex peptides, especially useful in synthesizing branched or modified peptides for research in drug development and biochemical studies. Commonly applied in the preparation of peptide-based probes and antigens.