反应详情

A solution of 11 (229 mg, 1.0 mmol) in THF (10 mL) was sequentially treated with BF3.OEt2 (0.13 mL, 1.05 mmol), n-BuLi (0.55 mL, 2.00 M, 1.10 mmol) and B(OEt)3 (0.20 mL, 1.20 mmol). Standard workup gave the extract, to which was added pinacol (138 mg, 1.10 mmol) and stirred at room temperature for 5 min. Concentration of the mixture under reduced pressure and column chromatography (basic alumina, hexanes) gave 12e (298 mg, 84%) as an orange oil that solidified on standing; mp 75-76° C. (pentane); IR (KBr) vmax 3090, 2978, 2833, 2785, 1141, 1077 cm−1; 1H NMR (300 MHz, acetone-d6) 4.18 (s, 5H), 4.16 (s, 1H), 4.08 (s, 2H), 2.65 (s, 6H), 1.32 (s, 12H) ppm; 13C NMR (75.5 MHz, acetone-d6) 119.6, 82.7, 71.9, 68.3, 67.5, 66.0, 60.1, 43.7, 24.4, 24.1 ppm; EIMS [m/z (%)] 355 (M+, 100), 255 (15), 121 (20); HRMS (EI) calcd for C18H26BNO256Fe: 355.1406. Found 355.1411. Anal. Calcd for C18H26BNO2Fe: C, 60.89; H, 7.38. Found: C, 60.96; H, 7.48.

1. customStandard workup gave the extract