This compound, (S)-tert-butyl 2-amino-6-(((benzyloxy)carbonyl)amino)hexanoate, also known as N^ε-Cbz-L-lysine tert-butyl ester, is a selectively protected derivative of L-lysine used in peptide synthesis. The tert-butyl group serves as a protecting moiety for the α-carboxyl group, while the benzyloxycarbonyl (Cbz) group protects the ε-amino group on the lysine side chain. The α-amino group is left unprotected, enabling direct coupling to a growing peptide chain. This orthogonal protection strategy allows for selective deprotection and prevents unwanted side reactions during the assembly of complex peptides containing lysine residues. It is particularly useful in pharmaceutical research for producing custom peptides and enantiomerically pure compounds essential in medicinal chemistry.