反应详情

温度

5 °C

A solution of the product of Example 311B (0.739 g) in toluene (20 mL) and hexadecyltributylphosphonium bromide (0.128 g, 0.25 mmol) at 0° C. was treated dropwise with a solution of sodium borohydride (0.109 g, 2.9 mmol) in water (0.80 mL). The reaction was stirred at 25° C. for 18 hours and at 5° C. for 72 hours. The reaction was extracted with ethyl acetate. The organic layer was washed with 1N aqueous sodium hydroxide, water, and brine and dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by column chromatography on silica gel, eluting with a gradient of 1:1 hexanes/dichloromethane to 100% dichloromethane to give the title compound (0.252 g, 23%). 1H NMR (300 MHz, CDCl3)δ ppm 6.36 (s, 1 H) 4.93 (br s, 2 H) 4.60 (br s, 1 H) 1.30 (s, 9 H).

1. extractionThe reaction was extracted with ethyl acetate
2. washThe organic layer was washed with 1N aqueous sodium hydroxide, water, and brine
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by column chromatography on silica gel
7. washeluting with a gradient of 1:1 hexanes/dichloromethane to 100% dichloromethane