Diethyl Ether → 2,2,6-Trichloro-6-fluoro-1,1-cyclohexane-diol

0.96 g (4.33 mmol) of trichlorofluoro alcohol 1b in solution in 10 cm3 of dichloroethane were introduced into a 25-cm3 round bottom flask fitted with a condenser and with magnetic stirring. 2.33 g (2.5 eq.) of PCC were added with a spatula and the mixture was heated to reflux under argon atmosphere for 7 h. The reaction mixture was allowed to cool and was then taken up with 100 cm3 of ether, the whole being filtered on florisil. The solvents were evaporated off, the residue was incorporated on silica and purified by flash chromatography (eluent: ether/petroleum ether=15/85 then 20/80). 0.03 g of starting alcohol 1b, that was approximately 3%, and 0.05 g of a mixture of alcohol 1b, diol 3a and 0.76 g of pure diol 3a were isolated. The yield of compound was therefore higher than 74%.