4, X= OCOCH, its 1-hydroxy-1, 2-benziodoxolin-3-one valence tautomeric form (2). l Cogent support for this proposal appeared in 1965.2 From the anomalously high pK, of 1 or 2 (variously given as 6.222 or 7.43), we infer that its conjugate base, anion 3, could be a potent 0 nucleophile near neutral pH. However, despite its well-established biochemical role as an oxidant of protein thiol group^,^ the nucleophilic properties of o-iodosobenzoic acid ...
