Ceric ammonium nitrate, reaction with epoxides

Reaction of 6 (3-hydroxy-steroids with ceric ammonium nitrate was reported to give the 6(3, 19-epoxides,123 and fragmentation of 5- and 19-hydroxy-compounds were also reported. A detailed investigation of the hypoiodite reaction and the related Pb(OAc)4 oxidation of a 5a-bromo-6(3-hydroxy-compound indicated that for the former a halocarbon solvent promotes 6(3,19-epoxide formation.124 Photolysis of the 17a-iodobenzoate (148) with PhICI2 gave the 9 -chloro-derivative (149) which on thermolysis gave a good yield of the 9(11), 16-diene (150).125 Photolysis of... 

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