The preparation of chlorinated hydrocarbons, such as pentachloropropanes, such as 1,1,1,2,3-pentachloropropane, from tetrachloropropanes, such as 1,1,1,3-tetrachloropropane, in the presence of a polyvalent antimony compound that includes a pentavalent antimony compound, such as antimony pentachloride, is described. Also described are methods for preparing optionally chlorinated alkenes, such as, tetrachloropropenes, from chlorinated alkanes, such as pentachloropropanes, in the presence of ferric chloride and a polyvalent antimony compound that includes a pentavalent antimony compound.