Fmoc-D-Dab(Dde)-OH is widely used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). Its primary application lies in the protection of amino groups during the synthesis process. The Fmoc (9-fluorenylmethoxycarbonyl) group serves as a temporary protecting group for the amino group, allowing selective deprotection under mild basic conditions. The Dde (1-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl) group acts as an orthogonal protecting group for side-chain amino groups, enabling selective removal in the presence of Fmoc. This dual protection strategy is crucial for synthesizing complex peptides with multiple functional groups, as it allows precise control over the sequence and structure of the peptide. Additionally, Fmoc-D-Dab(Dde)-OH is valuable in the synthesis of peptides containing unnatural amino acids or modified side chains, which are often required in drug development and biochemical research. Its stability and compatibility with standard SPPS protocols make it a versatile tool in peptide chemistry.