Journal of the Serbian Chemical Society 2004 Volume 69, Issue 11, Pages: 941-947
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Electrochemical chlorination of some 5-unsaturated steroids
Milisavljević Smiljka, Vukićević Rastko D.
Five 5-unsaturated steroids were subjected to constant current electrolysis (50 mA) in a dichloromethane solution of tetraethylammonium chloride in an undivided electrolytic cell at room temperature, using a graphite stick as the anode and a cooper spiral as the cathode. The addition of electrochemically generated elemental chlorine onto the double bond of cholesterol derivatives (5-cholestene, cholesteryl acetate, cholesteryl benzoate and 3-chloro-5-cholstene) gave the corresponding 5α,6β -dichlorosteroids, in good yields (70–73 %). The obtained compounds (5α,6β -dichlorocholestane, 5α,6β -dichlorocholestane-3β -yl acetate, 5α,6β -dichlorocholestane-3β -yl benzoate and 3β, 5α,6β -trichlorocholestane) were characterized by physical and spectral data (IR, 1 H–NMR and 13 C–NMR). However, under the same reaction conditions, cholesterol produced amixture of products from which the expected dichloro derivative (3 -hydroxy- 5 ,6 -dichlorocholestane) could not be isolated. This compound was prepared by alkaline hydrolysis of 5α,6β-dichlorocholestan-3β -yl acetate and 5α,6β -dichlorocholestan- 3β -yl benzoate in methanol.
Keywords: electrolysis, electrochemical chlorination, 5-unsaturated steroids, 5α,6β-dichlorosteroids