反应详情

A cooled (0° C.) solution of 30A (15.0 g, 64.8 mmol) and imidazole (22.0 g, 324 mmol) in dry DMF (110 ml) was treated with tert-butyldimethylsilyl chloride (24.3 g, 162 mmol), warmed to RT and stirred for 24 h. The reaction mixture was treated with methanol (150 ml), stirred at RT for another 24 h then partitioned between 10% aqueous citric acid (225 ml) and EtOAc (3×1.0 L). The extracts were washed with brine (200 ml), dried (Na2SO4) and filtered. The filtrate was concentrated to dryness to give a thick colorless syrup (46.0 g). Purification of a portion (20 g) by using automated flash chromatography (135 g silica gel column, EtOAc/hexane gradient) gave the title compound as a thick clear syrup (9.7 g, 99.7%).

1. stirringstirred at RT for another 24 h
2. customthen partitioned between 10% aqueous citric acid (225 ml) and EtOAc (3×1.0 L)
3. washThe extracts were washed with brine (200 ml)
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. concentrationThe filtrate was concentrated to dryness