Ethylene was bubbled into 7.3 (882 mg, 1.86 mmol) in 40 mL ACN at room temperature for 20 minutes. (Boc)2O (610 mg, 2.79 mmol) was added at room temperature, followed by the addition of DMAP (23 mg, 0.19 mmol). The mixture was stirred at room temperature for 6 hours. After HPLC indicated that all the 7.3 was consumed, the reaction mixture was taken into EtOAc (500 mL) and saturated sodium bicarbonate (400 mL). The organic layer was separated, washed with brine, dried, and concentrated under vacuum. The crude product was purified by flash chromatography to give 9.1 800 mg). MS ESI (pos.) m/e: 485 (M+H).
