The Reaction of Enols with Superoxide Anion Radicals: Preparation of Tertiary α-Ketols
Pregnan-20-ones (1) and (4) and 3β-hydroxy-5α-cholestan-6-one (7) react with KO2 and 18-crown-6 benzene solution and under an oxygen atmosphere at 6-7 deg C to give the corresponding α-hydroperoxides (2), (5), and (8) which after treatment with Ph3P gives α-ketols (3), (6), and (9) in good yields.