Boron tribromide → HCID 60171588, compound

Participants

Reaction Conditions

Reaction Steps

A stirred solution of 13 (0.0500 g, 0.135 mmol, 1 equiv) in CH2Cl2 (7 mL) was enclosed in aluminum foil and cooled 0° C. To the stirred solution was added dropwise BBr3 (1 M in CH2Cl2; 0.677 mL, 0.677 mmol, 5 equiv). The resulting solution was allowed to slowly warm to room temperature and stir for 18 h. The reaction mixture was quenched with a saturated aqueous solution of NaHCO3 (8 mL) and allowed to stir at room temperature for an additional hour. The solution was acidified with HCl, extracted with EtOAc (×2) and the combined organic layers were dried (MgSO4), filtered, and concentrated under reduced pressure. The crude product was purified by chromatography on SiO2 (chloroform/acetone, 3:1) to give 0.0462 g (96% yield) of 14 as a slight yellow film. An analytically pure sample was obtained via SFC chromatography using the semi-prep (250×10 mm) silica column (RT=4.68 min, 8 mL/min, 25% methanol, 220 nm detection): Rf 0.15 (acetone/chloroform, 2:8); IR (neat) 3343, 1692, 1599, 1495, 1417, 1329, 1184, 1143, 1005, 822 cm−1; 1H NMR (600 MHz (CD3)2CO) δ 8.17 (bs, 4 H), 6.86 (s, 1 H), 6.84 (s, 1 H), 6.29 (d, 2 H, J=2.4 Hz), 6.32 (t, 1 H, J=7.8 Hz), 3.69 (s, 2 H), 3.47 (d, 2 H, J=7.8 Hz); 13C NMR (150 MHz, CDCl3) δ 159.5, 149.0, 146.9, 140.5, 133.7, 128.0, 127.0, 118.5, 118.5, 116.7, 108.0, 101.8, 40.2, 29.5; HRMS (ES−) [2M-H]− m/z calcd for C32H27O8Cl4 679.0460, found 679.0482.

Provenance & Evidence