反応手順
To a two-necked, round bottom flask (250 mL) equipped with a magnetic stirrer, pressure equalizing funnel and rubber septum was suspended oil free potassium hydride (2.23 g, 55 mmol, 1.5 eq) in tetrahydrofuran (THF, 25 mL). 4-Phenylphenol (6.30 g, 37 mmol, 1 eq) in THF (50 mL) was then added drop-wise with stirring for over 20 min via the funnel. After the evolution of hydrogen was complete, the orange-yellow slurry was cooled to −78° C., and then treated with drop-wise solution of trichloroethylene (5.8 g, 44 mmol, 1.2 eq) in THF (25 mL) for over 10 min. The cooling bath was removed and the reaction mixture was allowed to warm to room temperature (rt) and then maintained for overnight (12 h). To the dark brown mixture was carefully added water (10 mL) using a syringe and then partitioned between water (200 mL) and ethyl acetate (200 mL). The organic phase was then washed with brine (200 mL). Extraction of the combined aqueous layers was done using ethyl acetate (150 mL×3). The combined organic phases were dried over anhydrous magnesium sulfate, filtered and concentrated using the rotary evaporator to give yellowish brown oil. Silica gel (200 g) column chromatography was done using hexane as eluent to afford 2 (10.5 g, 85%) as colorless oil that later crystallized to white crystals: mp 52-55° C. 1H NMR (300 MHz, CDCl3): 7.62-7.54 (m, 4H, HAr), 7.48-7.41 (m, 2H, HAr), 7.39-7.32 (m, 1H, HAr), 7.18-7.12 (m, 2H, HAr), 6.00 (s, 1H, HC(Cl)═C(O)) ppm; 13C NMR (75 MHz, CDCl3): 153.3, 140.2, 137.8, 128.8, 128.5, 127.3, 127.0, 117.4, 103.9 ppm; IR (cm−1): 3105, 3031, 1898, 1658, 1630, 1603, 1585, 1543, 1310, 1203, 1184, 1107, 1074, 1008, 996, 915, 863, 840, 641, 547, 511; HRMS (ESI) Calculated for C14H10Cl2O [M−H]− 263.0031. Found 263.0030; Elemental analysis Calculated. for C14H20Cl2O.0.02H2O: C, 63.33; H, 3.81. found: C, 63.34; H, 3.79.
