(Trifluoromethyl)trimethylsilane → Tert-butyl 4-hydroxy-4-(trifluoromethyl)piperidine-1-carboxylate

Tetrabutylammonium fluoride (50 mg, 1M solution in tetrahydrofuran) was added to an ice-cooled solution of (trifluoromethyl)trimethylsilane (2.1 g, 15 mmol) and tert-butyl 4-oxo-1-piperidinecarboxylate (2 g, 10 mmol) in tetrahydrofuran (20 ml), and the reaction stirred at room temperature for 18 hours. The mixture was concentrated under reduced pressure, the residue suspended in ethyl acetate, hydrochloric acid (20 ml, 1N) was added, the mixture stirred for an hour, and then neutralised using sodium bicarbonate. The solution was washed with water, then brine, dried (MgSO4) and evaporated under reduced pressure to give a gum. This was purified by column chromatography on silica gel using an elution gradient of dichloromethane:methanol (100:0 to 98:2) to afford the title compound, 1.94 g.