To a solution of 4.9 g (15.8 mmol) of the above 4-(5-fluoro-2-methoxyphenyl)-4-methyl-2-trifluoromethylpentane-1,2-diol in 100 mL of MeOH was added 10 g (45.9 mmol) of sodium periodate. The mixture was stirred for 4 hours and was then diluted with 100 mL of ether and 100 mL of hexane, filtered through diatomaceous earth and concentrated in vacuo. The crude residue was dissolved in hexane and passed through a pad of silica gel, eluting first with hexane then with EtOAc-hexane (2:98, then 4:96) to afford 3.85 g (87%) of the title compound as a clear oil.
