To a flame-dried 50-mL round-bottomed flask equipped with a magnetic stir bar was added crude oxime 12-10 as a solution in 1:2 DMF:CH2Cl2 (1.9 mL, 1.0 M). The reaction vessel was then moved to an ice-water cooled to 0 °C. To the reaction mixture was added imidazole (448 mg, 6.58 mmol, 3.5 equiv) and TBSCl (425 mg, 2.82 mmol, 1.5 equiv), and the reaction vessel was removed from the ice-water bath and allowed to warm to room temperature.