反应详情

温度

0 °C

The product from step (a) (0.79 g, 4.58 mmol) was dissolved in dimethylformamide (5 ml) and triethylamine (1.28 ml, 9.16 mmol) and 4-dimethylaminopyridine (0.02 g) added. The solution was cooled to 0° C. and t-butyldimethylsilylchloride (0.655 g, 4.35 mmol), as a solution in dimethylformamide (35 ml), was added dropwise over half an hour. The reaction was stirred at 0° C. for 2 h, then allowed to warm to room temperature slowly. After stirring for a further 18 h, water (50 ml) was added and the reaction extracted with ethyl acetate (3×70 ml). The combined extracts were washed with water (3×20 ml), dried (magnesium sulphate) and evaporated. The residue was chromatographed on flash silica, eluting with hexane:ethyl acetate (4:1) to give the title compound as a colourless oil (1.164 g, 89%).

1. temperatureto warm to room temperature slowly
2. stirringAfter stirring for a further 18 h
3. extractionthe reaction extracted with ethyl acetate (3×70 ml)
4. washThe combined extracts were washed with water (3×20 ml)
5. dry with materialdried (magnesium sulphate)
6. customevaporated
7. customThe residue was chromatographed on flash silica
8. washeluting with hexane:ethyl acetate (4:1)