After the reaction had stirred at 80 °C for one hour, the reaction vessel was removed from the oil bath and allowed to cool to room temperature. Once at room temperature, the reaction mixture was diluted with water (20 mL), and the layers were separated. The aqueous layer was extracted with Et2O (2 x 50 mL). The combined organic extracts were washed with brine (25 mL), dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure by rotary evaporation to provide a crude brown oil. Purification by flash column chromatography on silica gel (50% Et2O/hexanes to 75% Et2O/hexanes) afforded 3-1 (1.4 g, 36% over two steps) as a colorless solid.