After stirring at room temperature for one hour, the reaction vessel was again transferred to a 0 °C ice-water bath, and sat. aq. NaHCO3 (5 mL) was added dropwise to the reaction mixture. The layers were separated, and the aqueous layer was extracted with CH2Cl2 (3 x 20 mL). The combined organic extracts were washed with brine (15 mL), dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure by rotary evaporation to give a yellow oil. Purification by flash column chromatography on silica gel (10% EtOAc/hexanes to 30% EtOAc/hexanes) afforded 10-3 (159 mg, 43%) as a yellow foam.