反应详情

A molecular sieve 4A (3.14 g) and a boron trifluoride-diethyl ether complex (2.16 mL, 17.5 mmol) were added to methylene chloride (31 mL), and the mixture was stirred at room temperature for 1 hour. Subsequently, paraformaldehyde (0.46 g, 14.6 mmol) and the compound (3.14 g, 14.6 mmol) obtained in Example 91a were added at −5° C., and the mixture was stirred at the same temperature for 18 hours. After the reaction was completed, a saturated aqueous sodium hydrogencarbonate solution was added, and ethyl acetate was further added to separate the layers. The resulting organic layer was separated, washed with saturated sodium chloride solution, and then dried with anhydrous sodium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=5:1→3:1, v/v) to give the title compound (1.24 g; yield, 35%) as a colorless oily substance.

1. stirringthe mixture was stirred at the same temperature for 18 hours
2. customto separate the layers
3. customThe resulting organic layer was separated
4. washwashed with saturated sodium chloride solution
5. dry with materialdried with anhydrous sodium sulfate
6. customthe solvent was evaporated under reduced pressure
7. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=5:1→3:1, v/v)