Oxidation of propane-1,2-diol by acidic manganese(V) and manganese(VI)

Propane-1,2-diol (PD) reacts rapidly and selectively with unstable manganese(V) and manganese(VI) in acidic aqueous solution, thereby suppressing the known disproportionation of these species. Manganese(V) was generated by reducing the MnO4 ion with As(III), whereas manganese(VI) was produced by rapid acidification of a stable alkaline solution in the presence of PD, both in a stopped-flow device. The organic and Mn products were analyzed spectrometrically. The oxidation of propene by MnO4 yields the same product as PD with Mn(V), which is evidence for a common intermediate and a related mechanism.