Experimental To a solution of 22 (12.12 g, 26.27 mmol) and triethylsilane (8.40 ml, 52.6 mmol) in CH2Cl2 (300 ml) was added titanium tetrachloride (5.76 ml, 52.6 mmol) at 0 oC, and the solution was stirred for 1 hour. After dilution with CH2Cl2, the reaction mixture was quenched with saturated aqueous sodium hydrogen carbonate, and the resulting mixture was stirred for additional 15 minutes. The resulting suspension was filtered through pad of Celite, and the filter cake was washed with CH2Cl2 three times. The combined organic layer was washed with brine, dried over sodium sulfate, and filtered. The filtrate was concentrated in vacuo and the residue was purified with flash column chromatography (5% methanol in CH Cl ) to afford 23 (10.24 g, 92.95%) as a brown oil.