A stirred suspension of 8-fluoro-5-(4-methoxyphenylsulfonyl)-6-methyl-5,6-dihydrophenanthridine (1.26 g, 3.29 mmol) and cyclohexene (6.0 mL, 59 mmol) was treated drop-wise with a solution of 1 M boron tribromide (20 mL, 20 mmol) in dichloromethane at room temperature under nitrogen. After stirring for 20 hours at room temperature, a saturated, aqueous, sodium bicarbonate solution (300 mL) was added drop-wise, and the resulting mixture extracted with dichloromethane (6×20 mL). The combined organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The crude material was purified by flash column chromatography on silica gel, eluting with a mixture of ethyl acetate-hexane (1:19 to 1:4 gradient), followed by re-crystallization from a mixture of dichloromethane-hexane to yield the title compound as a homogeneous, white, crystalline, solid (1.1 g, 90%). The melting point, mass spectum, and NMR spectrum of this product were identical to the authentic material prepared in Example 32, Method A, Step e.
