A 50 mL round-bottom flask was charged with a magnetic stir bar, 5 (568 mg, 2 mmol, 1 equiv.), and THF (10 mL). The reaction mixture was cooled to 0 °C using an ice-water bath. TBAF (1 M in THF, 4 mL, 4 mmol, 2 equiv.) was added, and the reaction mixture was warmed to room temperature over a period of 12 h. Following this time, the solvent was evaporated under reduced pressure. The resulting residue was purified by column chromatography on Florisil by eluting with hexane/ethyl acetate (30/70 mixture) to afford 6 (brown oil, 0.170 g, 1 mmol, 50%).