Cbz-Phe-Thr(tBu)-OMe is a protected dipeptide used in peptide synthesis. The Cbz (Carbobenzyloxy) group protects the N-terminus of the phenylalanine (Phe) residue, preventing it from participating in unwanted reactions during the synthesis. The Thr (Threonine) residue is protected at its hydroxyl side chain by a tBu (tert-butyl) group, safeguarding this functional group until selective deprotection is needed. The OMe (methyl ester) at the C-terminus indicates that the carboxyl group is esterified, which can be useful in certain synthetic strategies to prevent reactions at the carboxyl end. This compound is used to introduce phenylalanine and threonine into peptides while maintaining control over the reactivity of the functional groups.