After stirring at room temperature for 30 minutes, sat. aq. NaHCO3 (25 mL) was added to the reaction mixture. The layers were separated and the aqueous layer was extracted with CH2Cl2 (3 x 25 mL). The combined organic extracts were washed with brine (30 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 (5% Et2O/hexanes to 15% Et2O/hexanes) afforded 10-8 (694 mg, 88%) as a colorless oil. Rf: 0.22 (10% Et2O/hexanes, KMnO4)