Highly efficient propane-1,3-dithiol mediated thiol–disulphide interchange: a facile and clean methodology for S–S reduction in peptides

Propane-1,3-dithiol, at room temperature and in the absence of any promoter, neatly brings about the S–S → 2SH change, and the latter can be isolated as acrylonitrile adducts; the methodology has been tested with several substrates including c-lysozyme, insulin and oxytocin, and spontaneous imidazole promoted S-deprotection was observed in the case of Z-Cys(S-CH2CH2CN)His-OMe.