反应详情

tert-Butyl 2-(dimethoxyphosphoryl)acetate (2.5 mL, 12.7 mmol) was added dropwise to a suspension of NaH (490 mg, 12.7 mmol, 60% dispersion in oil) in THF (60 mL) at 0° C. After stirring for 30 min at ambient temperature a solution of 53A (2.6 g, 11.4 mmol) in THF (10 mL) and stirred for 1 h at ambient temperature. The reaction mixture was poured into 50 mL saturated NaHCO3/400 mL water and extracted with diethyl ether. The combined organics were dried over Na2SO4 and concentrated in vacuo. The crude solid was purified by flash chromatography (0% to 50% EtOAc in hexanes) to yield 53B (2.35 g, 63%) as a white solid. 1H NMR (400 MHz, CDCl3) δ ppm 1.44 (s, 9 H) 2.22 (s, 6 H) 3.43 (dd, J=5.56, 1.77 Hz, 2 H) 5.43 (dt, J=15.54, 2.02, 1.89 Hz, 1 H) 6.92 (dt, J=15.66, 5.56 Hz, 1 H) 7.17 (s, 2 H).

1. extractionextracted with diethyl ether
2. dry with materialThe combined organics were dried over Na2SO4
3. concentrationconcentrated in vacuo
4. customThe crude solid was purified by flash chromatography (0% to 50% EtOAc in hexanes)