Hydrochloric Acid → 1-(4-(2-(Ethoxymethoxy)propan-2-yl)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethanone
反応式
[CH2:1]([O:3][CH2:4][O:5][C:6]([C:9]1[CH:14]=[CH:13][C:12]([C:15]([O:18]COCC)(C)[CH3:16])=[CH:11][C:10]=1[B:23]1[O:27][C:26]([CH3:29])([CH3:28])[C:25]([CH3:31])([CH3:30])[O:24]1)([CH3:8])[CH3:7])[CH3:2].Cl>C1COCC1>[CH2:1]([O:3][CH2:4][O:5][C:6]([C:9]1[CH:14]=[CH:13][C:12]([C:15](=[O:18])[CH3:16])=[CH:11][C:10]=1[B:23]1[O:27][C:26]([CH3:29])([CH3:28])[C:25]([CH3:30])([CH3:31])[O:24]1)([CH3:7])[CH3:8])[CH3:2]参加物
4
実験手順
To a solution of 2-(2,5-bis(2-(ethoxymethoxy)propan-2-yl)phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (510 mg) in THF (15 mL) was added 6 N HCl (3.8 mL). The reaction mixture was stirred at rt for 5 h, and extracted with DCM (200 mL×2). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by Combiflash to give 6-(2-hydroxypropan-2-yl)-3,3-dimethylbenzo-[c][1,2]oxaborol-1(3H)-ol [112 mg, yield 45% (2 steps, step 5 and 6)] as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 8.93 (s, 1H), 7.77 (s, 1H), 7.57 (d, J=8.0 Hz, 1H), 7.32 (d, J=8.0 Hz, 1H), 4.98 (s, 1H), 1.43 (s, 12H) ppm; HPLC purity: 94.6% at 220 nm and 100% at 254 nm; MS: m/z=203.1 (M−17, ESI+).