The invention relates to a process for introducing a thiol group a to a carbonyl group in a side chain of a protected a-amino acid, said protected a-amino acid having protecting groups on both the α-amine group and the a-carboxyl group. The process comprises a) if the side chain contains a functional group comprising a heteroatom bearing a hydrogen atom, protecting said functional group; b) treating the protected amino acid with a base of sufficient strength to abstract a hydrogen atom a to the carbonyl group, so as to form an anion; c) treating the anion with a reagent of structure Pr-S-L in which L is a leaving group and Pr is a thiol-protecting group, so as to introduce a Pr-S- group a to the carbonyl group; and d) converting the Pr-S- group to an H-S-(thiol) group. This process may be used to prepare ligated peptides.
该发明涉及一种将巯基引入受保护的
α-氨基酸侧链中的羰基的过程,所述受保护的
α-氨基酸在α-
氨基团和α-羧基团上均具有保护基。该过程包括a) 如果侧链含有包含带有氢原子的杂原子的官能团,则保护该官能团;b) 用足够强度的碱处理受保护的
氨基酸,以提取到羰基的氢原子,从而形成负离子;c) 用具有结构Pr-S-L的试剂处理该负离子,其中L是一个离去基团,Pr是一个巯基保护基,以引入Pr-S-基团到羰基;d) 将Pr-S-基团转化为H-S-(巯基)基团。该过程可用于制备连接的肽。