Dodecafluoroheptanoic Acid: the Fluoro Alcohol Oxidised with Permanganate (Berry 1951)

Permanganate turns the CH2OH end of the fluoro alcohol into an acid group. The acid comes out first as its manganese salt; dilute sulphuric acid frees it, ether takes it up, and distillation gives the clean acid at 190–193 °C. Its salts are soaps strong enough to keep PTFE particles apart in water. Source: K. L. Berry (du Pont), US 2,559,629 (1951), Example I. The apparatus is ours. Sulphur dioxide is a poisonous gas: work in a fume hood. Picture drawn by Youblob.