Efficient synthesis of vinyl chlorides and/or gem-dichlorides from ketones by treatment with tungsten hexachloride

Treatment of cyclic ketones, e.g. 4, with tungsten hexachloride (WCl6) provided good yields of vinyl chlorides, e.g. 5, and/or gem-dichlorides. A trans-diequatorial dichloride 9 was prepared by treatment of the corresponding epoxide 8 with WCl6.