Imidazole → (S)-methyl 2-(tert-butyldimethylsilyloxy)-3-ethoxypropanoate

Beteiligte Stoffe

Reaktionsschritte

A solution of tert-butylchlorodimethylsilane (17.71 g, 117.52 mmol) in dry DMF (50 mL) was added dropwise to a stirred solution of (S)-methyl 2-hydroxy-3-ethoxypropanoate (14.51 g, 97.94 mmol) and 1H-imidazole (13.33 g, 195.87 mmol) in dry DMF (70 mL) at 20° C., over a period of 2 minutes. The resulting solution was stirred at ambient temperature for 20 hours. The reaction mixture was concentrated and diluted with EtOAc (500 mL), washed sequentially with water (4×100 mL) and saturated brine (100 mL). The organic layer was dried (MgSO4) and evaporated. The residue was purified by flash silica chromatography, elution gradient 20 to 50% EtOAc in isohexane to afford methyl (2S)-2-(tert-butyl-dimethylsilyl)oxy-3-ethoxypropanoate (14.8 g, 57%). 1H NMR (400 MHz, CDCl3) δ 0.10 (6H, d), 0.93 (9H, s), 1.19 (3H, t), 3.50-3.65 (3H, m), 3.57-3.73 (1H, m), 3.75 (3H, s), 4.37-4.40 (1H, m), 7.18 (2H, d).

Herkunft & Nachweise