Bismethylenedioxy removal

Sodium Salt (54)3717a,20 20,21-Bismethylenedioxy-1, 2 -dihydroxypregn-4-ene-3, l-dione (53).37 A solution of 100 g of 17a,20 20,21-bismethylene-dioxypregna-l,4-diene-3,ll-dione (prednisone BMD) (52) in 720 ml of pyridine is cooled to 5° and treated with a solution of 69.9 g of osmium tetroxide in 408 ml of pyridine. The mixture, which turns black within 5 min is allowed to stand at room temperature for five days and then is added with stirring to 13.4 liters of petroleum ether. The crude osmate ester is isolated by filtration and washed with petroleum ether to remove most of the residual pyridine. The crude product is dissolved in 8 liters of dioxane and kept in an ice bath while a slow stream of hydrogen sulfide is bubbled through the reaction mixture. The precipitated osmium sulfide is removed by filtration, and the filtrate is concentrated to dryness in vacuo. The residual foam is dissolved in 2 liters of acetone, decolorized with activated carbon, filtered and concentrated to a volume of 1 liter. Addition of 1 liter of Skellysolve B affords 38 g of diol (53) A OH 236 mfi (e 14,100). 

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