Cbz-Ser(tBu)-Ser(tBu)-Gly-OH is a protected tripeptide used in peptide synthesis. The Cbz (Carbobenzyloxy) group protects the N-terminus of the serine (Ser) residue, preventing it from participating in unwanted reactions during synthesis. The hydroxyl groups on both serine residues are protected by tBu (tert-butyl) groups, which keep these groups from reacting until they are selectively deprotected. Gly (Glycine) is the final amino acid in the sequence, and the -OH at the C-terminus indicates a free carboxyl group. This free carboxyl group allows for further peptide coupling or modification. This compound is used to incorporate serine and glycine into peptides while maintaining control over the reactivity of functional groups through specific protection strategies.