To a dry 15 mL flask was added lithium aluminum hydride (233 mg, 6.0 mmol) and anhydrous diethyl ether (3 mL). The mixture was cooled with an ice bath. A solution of Example 1C (538 mg, 1.54 mmol) in anhydrous diethyl ether (3 mL) was slowly added with vigorous stirring. The bath was removed and the slurry was stirred for 15 minutes. The reaction was quenched with water (0.233 mL), aqueous 15% sodium hydroxide (0.233 mL) and water (0.699 mL). The white solid was filtered and the filtrate was dried over magnesium sulfate, filtered, and concentrated under reduced pressure to give a clear oil. The oil was then dissolved in anhydrous dichloromethane (10 mL) and manganese(IV) oxide (500 mg, 5.8 mmol) was added to the solution. The mixture was stirred for 12 hours. Filtration through diatomaceous earth (Celite®) followed by concentration of the filtrate under reduced pressure afforded 395 mg of crude product. Column chromatography [silica gel; eluent pentane-ethyl acetate (2:3)] provided the desired product (225 mg, 49%). 1H (CDCl3) δ(ppm): 1.55-1.61 (m, 2H); 1.65-1.68 (m, 2H); 2.61 (t, 2H); 3.17 (t, 2H); 3.64 (t, 2H); 4.79 (t, 2H); 7.12 (d, 2H); 7.23 (d, 2H); 7.56 (t, 1H); 7.82 (t, 1H); 7.93 (d, 1H); 8.14 (d, 1H); 8.77 (s, 1H). 13C (CDCl3) δ(ppm): 27.52, 32.31, 34.89, 35.21, 62.81, 67.74, 116.67, 123.54, 127.08, 127.49, 128.63, 128.98, 133.61, 135.23, 140.64, 150.68, 154.29, 166.79.
