A Highly Efficient, Indirect Electrooxidation of 6β-Methyl-3β,5α-dihydroxy-16α,17α-cyclohexanopregnan-20-one to the Corresponding 5α-Hydroxy-3,20-dione Using a Mediatory Couple of Sodium Bromide and Substituted 2,2,6,6-Tetramethylpiperidine-N-oxyl (TEMPO)

6β-Methyl-3β,5α-dihydroxy-16α,17α-cyclohexanopregnan-20-one 1, when electrolysed in the presence of 4-substituted TEMPO in a two-phase system of CH₂CI₂–aqueous NaBr, is oxidised chemoselectively and in high yield into 6β-methyl-5α-hydroxy-16α,17α-cyclohexanopregnan-3,20-dione 2.