Selective removal of sulphur protecting groups of cysteine residues by sulphenyl halides
Abstract
Sulphur protecting groups of cysteine, such as triphenylmethyl, diphenylmethyl, 4,4′-dimethoxydiphenylmethyl and acetamidomethyl groups, are cleanly removed by the action of 2-nitrophenylsulphenyl chloride in acetic acid and subsequent reduction of the S-(2-nitrophenylsulphenyl)cysteine residues formed to regenerate the thiol function.