反应详情

To a solution of the compound obtained in Step B (6.2 g/0.03 mol) in 100 ml of CH2Cl2 there are added, in succession, pyridine (4.9 ml/0.06 mol), DMAP (1.83 g/0.015 mol), and then, dropwise, acetic anhydride (5.7 ml/0.06 mol). The whole is then stirred at room temperature for 24 hours. The reaction mixture is then concentrated to dryness, taken up in AcOEt, washed with a dilute HCl solution (1N), a saturated NaHCO3 solution and then with a saturated NaCl solution; dried over MgSO4 and then concentrated to dryness. The residual yellowish oil is then purified by chromatography over silica gel to yield the title product in the form of white crystals.

1. concentrationThe reaction mixture is then concentrated to dryness
2. washwashed with a dilute HCl solution (1N)
3. dry with materialdried over MgSO4
4. concentrationconcentrated to dryness
5. customThe residual yellowish oil is then purified by chromatography over silica gel