ACTIVATION OF CONVENTIONAL S-PROTECTING GROUPS OF CYSTEINE BY CONVERSION INTO THE 3-NITRO-2-PYRIDINESULFENYL (NPYS) GROUP

Article abstract of DOI:10.1246/cl.1982.921

All the conventional S-protecting groups of cysteine which were tested could be selectively converted to the 3-nitro-2-pyridine-sulfenyl (Npys) group after treatment with an appropriate Npys halide.Unidirectional formation of an unsymmetrical disulfide bond is possible when Cys(Npys) is mixed with a free thiol of another Cys residue.Some of these features were exploited during the solid phase synthesis of lysine⁸-vasopressin.