Treatment of 5α,6α-epoxy-3β-methylsulphonyloxyandrostan-17-one with lithium bromide and lithium carbonate in dimethylformamide afforded androst-4-ene-6,17-dione. Dehydrogenation of this with dichlorodicyanobenzo-quinone gave androsta-2,4-diene-6,17-dione. This was also prepared by oxidation of the epoxide to the 5α-hydroxy-6-ketone followed by elimination of the methanesulphonate group with lithium carbonate and dehydration of the 5α-alcohol with thionyl chloride.