Synthesis of Disulfide Surrogate Peptides through a Serine/Threonine Ligation-Assisted Diaminodiacid Strategy.

We report a new serine/threonine ligation (STL)-assisted diaminodiacid (DADA) strategy for the flexible construction of disulfide surrogates by the option of more abundant -Aa-Ser/Thr- ligation sites. The practicality of this strategy was evidenced by the synthesis of the intrachain disulfide surrogate of C-type natriuretic peptide and the interchain disulfide surrogate of insulin.