反应详情

Compound 2a (2.297 g, 7.26 mmol) was dissolved in anhydrous pyridine (20 mL) at RT under argon. Imidazole (1.02 g, 14.52 mmol) in anhydrous pyridine (10 mL) was the added followed by tert-butyl dimethylsilyl chloride (TBDMS-Cl, 2.25 g, 14.52 mmol) in anhydrous pyridine (20 mL). The reaction mixture was stirred at RT for 72 hours, poured into 0.5 M H2SO4 (150 mL) and extracted with diethyl ether (100 mL, 3×), The extract was washed successively with saturated aqueous NaHCO3 (100 mL) and water (100 mL), dried over anhydrous Na2SO4 and the solvent removed under reduced pressure to obtain 3a, an oily material which was dried in a vacuum dessicator for 2 days (3.164 g, 100% yield). 1H NMR (in CDCl3): δ in ppm 0.83-0.89 (15H, m), 1.22 (29H, m), 1.52-1.53 (2H, m), 2.60 (1H, s, D2O exchangeable), 3.40-3.42 (4H, m), 3.59-3.61 (2H, m), 3.64 (1H, m); 13C NMR (in CDCl3): δ in ppm 14.3, 18.2, 18.5, 22.9, 25.8, 26.0, 26.1, 26.3, 29.6, 29.8, 29.9, 32.1, 33.0, 64.2, 70.8, 71.6, 71.9.

1. extractionextracted with diethyl ether (100 mL, 3×)
2. washThe extract was washed successively with saturated aqueous NaHCO3 (100 mL) and water (100 mL)
3. dry with materialdried over anhydrous Na2SO4
4. customthe solvent removed under reduced pressure