反应详情

tert-Butyldiphenylsilylchloride (TBDPSCl) (1.8 mL, 1.96 g, 7.14 mmol) was added to a suspension of 5-methoxyresorcinol 18 (1.0 g, 7.14 mmol) and imidazole (729 mg, 10.71 mmol) in dry DMF (5 mL) under argon at −22° C. and the mixture was stirred for 10 min. The reaction mixture was diluted with H2O (25 mL) and extracted with EtOAc (3×25 mL). The combined organic extracts were washed with aq 1M of HCl (2×25 mL), and brine (2×25 mL). The organic layer was then dried (Na2SO4) and concentrated in vacuo. The crude silyl phenol 19 was purified by FCC on silica gel (5% ethyl acetate in hexane) to afford pure silyl phenol 19 (892 mg, 33%): 1H NMR (300 MHz, CDCl3) δ 7.89-7.75 (4H, m, HAr), 7.48-7.34 (6H, m, HAr), 5.98 (2H, t, J=2.1 Hz, HAr), 5.92 (1H, t, J=2.1 Hz, HAr), 5.13 (1H, br, s, HO—), 3.56 (3H, s, H3CO), 1.14 (9H, s, [(H3C)3C]; 13C NMR (75 MHz, CDCl3) δ 161.1, 157.3, 156.8, 135.4, 132.8, 129.9, 127.7, 100.1, 98.5, 95.0, 55.0, 26.4, 19.4; LRMS (CI), m/z (relative intensity): 378([M+1]+, 30), 321 (100), 243 (30), 213 (10), 199 (29). This material was employed directly in the next step.

1. extractionextracted with EtOAc (3×25 mL)
2. washThe combined organic extracts were washed with aq 1M of HCl (2×25 mL), and brine (2×25 mL)
3. dry with materialThe organic layer was then dried (Na2SO4)
4. concentrationconcentrated in vacuo
5. customThe crude silyl phenol 19 was purified by FCC on silica gel (5% ethyl acetate in hexane)