Boc-Pen(Trt)-Oh is widely used in peptide synthesis as a protected form of penicillamine. Its primary application is to facilitate the incorporation of penicillamine into peptide chains while preventing unwanted side reactions. The Boc (tert-butoxycarbonyl) group protects the amino group, and the Trt (trityl) group safeguards the thiol group during the synthesis process. This compound is particularly valuable in the production of peptides with specific structural or functional properties, such as those used in medicinal chemistry or biochemical research. After the peptide chain is assembled, the protecting groups can be selectively removed to yield the desired peptide with free amino and thiol functionalities.