To a flame-dried 50-mL round-bottomed flask equipped with a magnetic stir bar was added crude oxime SI-6 (900.0 mg, 4.58 mmol, 1.0 equiv) as a solution in 1:2 DMF:CH2Cl2 (4.5 mL, 1.0 M). The reaction vessel was then moved to a 0 °C ice-water bath. To the reaction mixture was added imidazole (1.09 g, 16.1 mmol, 3.5 equiv) and TBSCl (746 mg, 6.87 mmol, 1.5 equiv), and the reaction vessel was removed from the ice-water bath and allowed to warm to room temperature.