Fast, efficient and selective deprotection of the tert‐butoxycarbonyl (Boc) group using HCl/dioxane (4 m)

Abstract: Fast, efficient and selective deprotection of the tert ‐butoxycarbonyl (Boc) group of various amino acids and peptides was achieved by using hydrogen chloride (4 m ) in anhydrous dioxane solution for 30 min at room temperature. In the cases studied in our laboratory, this protocol provided superior selectivity to deprotect N α ‐Boc groups in the presence of tert ‐butyl esters and tert ‐butyl ethers, including thio‐ tert ‐butyl ethers, but not phenolic tert ‐butyl ethers.