反应详情

Sodium hydroxide (7.3 ml of 1M aqueous solution) followed by methanol (4 ml) were added to a solution of the product of step c) (2.28 g) in tetrahydrofuran (50 ml) and stirred at room temperature for 3 h. The solution was concentrated under reduced pressure. The residue was diluted with water and extracted with ethyl acetate. The combined extracts were dried over magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by flash silica chromatography eluting with a gradient of 2-5% ethanol in dichloromethane to give the sub-title compound as a white solid (1.68 g). MS (APCI) 445/447 [M+H]+. δ 1HCDCl3 0.96 (6H,d), 2.22 (1H, septet), 2.37 (3H,s), 3.51 (3H,s), 3.78 (2H,d), 5.78 (2H,s), 15.51 (1H,br.s).

1. concentrationThe solution was concentrated under reduced pressure
2. additionThe residue was diluted with water
3. extractionextracted with ethyl acetate
4. dry with materialThe combined extracts were dried over magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe residue was purified by flash silica chromatography
8. washeluting with a gradient of 2-5% ethanol in dichloromethane