反应详情

To a stirred solution of the product from Step B (1.18 g, 3.61 mmol) in anhydrous THF (40 mL) was added potassium hexamethyldisilazide (8.7 mL, 0.5M in toluene, 4.35 mmol) at −78° C. The resultant mixture was stirred at −78° C. for 30 min. A precooled solution of trisyl azide (1.56 g, 5.04 mmol) in THF (30 mL) was added via cannula. After 1.5 min the reaction was quenched with glacial acetic acid (0.95 mL, 16.6 mmol) and potassium acetate (1.77 g, 18.1 mmol). The cooling bath was removed, and the reaction was stirred at room temperature for 12 h. The solution was partitioned between ethyl acetate and brine. The aqueous phase was extracted with three portions of ethyl acetate. The organic phases were combined, washed with saturated aqueous sodium bicarbonate solution, dried over sodium sulfate, and evaporated in vacuo. Purification by flash chromatography (silica gel, 80:20 hexanes/ethyl acetate) afforded the desired product.

1. customThe cooling bath was removed
2. customThe solution was partitioned between ethyl acetate and brine
3. extractionThe aqueous phase was extracted with three portions of ethyl acetate
4. washwashed with saturated aqueous sodium bicarbonate solution
5. dry with materialdried over sodium sulfate
6. customevaporated in vacuo
7. customPurification by flash chromatography (silica gel, 80:20 hexanes/ethyl acetate)