To a solution of 1.0M potassium tert-butoxide in tetrahydrofuran (5.95 mL, 5.95 mmol) at 0° C. was added diethyl cyanomethylphosphonate (1.05 g, 5.95 mmol). The bath was removed and reaction allowed to warm to room temperature for 1 hour. The reaction was cooled to 0° C. and a solution of 3-{[tert-butyl(diphenyl)silyl]oxy}cyclobutanone (1.95 g, 6.01 mmol) in THF (10 mL) was added. Upon complete addition, the bath was removed and the reaction was allowed to warm to room temperature and stir overnight. The reaction solution was diluted with water and ethyl acetate. The aqueous layer was extracted with ethyl acetate three times. The combined extracts were washed with brine, dried over sodium sulfate, decanted and concentrated. The crude was purified silica gel column to give the desired product (2.07 g, 90%) as an oil. LCMS (M+H)+: 348.2.
