Fmoc-Tyr(But)-OH is a derivative of tyrosine, a crucial amino acid widely used in peptide synthesis and organic chemistry. The Fmoc (9-fluorenylmethyloxycarbonyl) group, combined with the tert-butyl (But) protecting group, provides stability and protection for specific functional groups during chemical reactions, enabling controlled synthesis of complex molecules. This compound finds extensive application in research, pharmaceutical development, and various organic synthetic processes due to its versatility and compatibility with diverse synthetic protocols.