反应详情

To a solution of 226 (237 mg, 0.45 mmol) in THF (10 ml) at 0° C. (ice-bath) was added TBAF (1.0 M in THF, 0.53 ml, 0.53 mmol). The reaction mixture was stirred at 0° C. for 18 h. water (10 ml) was added and the aqueous layer was extracted with EtOAc (3×). The combined organic layer were washed with brine (10 ml), dried (MgSO4) and concentrated in vacuo. Purification (flashmaster: 20 g, 100% hex to 100% EtOAc over 25 min) afforded the title compound (70 mg, 43%) as a colourless oil. 1H NMR (270 MHz; CDCl3) 1.18 (6H, s, 2×CH3), 2.66 (2H, s, CH2), 3.50 (2H, s, CH2), 3.65 (2H, s, CH2), 3.79 (3H, s, OCH3), 3.83 (3H, s, OCH3), 6.47 (1H, s, CH), 6.52 (1H, s, CH), 6.75-6.79 (1H, m, CH), 6.95-6.97 (2H, m, 2×CH), 7.21 (1H, t, J=8.0 Hz, CH). 13C NMR (100 MHz; CDCl3) 23.72 (CH3), 45.54 (CH2), 49.97 (CH2), 52.49 (C), 53.45 (CH2), 55.13 (OCH3), 55.86 (OCH3), 110.69 (CH), 111.73 (CH), 111.90 (CH), 114.09 (CH), 120.88 (CH), 125.60 (C), 126.86 (C), 129.11 (C), 142.41 (C), 143.49 (C), 144.99 (C), 159.59 (C). LC/MS (ES−) tr=1.85 min, m/z 326.27 (M−H)−. HRMS (ES+) calcd. for C20H26NO3 (M++H) 328.1907, found 328.1904.

1. additionwas added
2. extractionthe aqueous layer was extracted with EtOAc (3×)
3. washThe combined organic layer were washed with brine (10 ml)
4. dry with materialdried (MgSO4)
5. concentrationconcentrated in vacuo
6. customPurification (flashmaster: 20 g, 100% hex to 100% EtOAc over 25 min)