反应详情

(Diazomethyl)trimethylsilane (1.6 mL, 3.2 mmol) was added dropwise to a stirred, cooled (0° C.) mixture of (RS)-methyl α-(hydroxymethyl)-3,5-bis(trifluoromethyl)benzeneacetate (Description 7, 1.0 g, 3.2 mmol) and aqueous fluoroboric acid (48%, 585 mg, 3.2 mmol) in dichloromethane (10 mL) and the mixture was stirred at room temperature for 20 minutes. Further (diazomethyl)trimethylsilane (0.8 mL, 1.6 mmol) was added and the mixture was stirred at room temperature for 20 minutes. Further (diazomethyl)trimethylsilane (0.4 mL, 0.8 mmol)) was added and the mixture was stirred at room temperature for 20 minutes. Further (diazomethyl)trimethylsilane (0.4 mL, 0.8 mmol)) was added and the mixture was stirred at room temperature for 30 minutes, poured into water (40 mL) and extracted with dichloromethane (2×40 mL). The combined organic fractions were dried (MgSO4), the solvent was evaporated under reduced pressure and the residue was purified by flash column chromatography on silica gel, eluting with isohexane/EtOAc (90:10), to give the title compound as a colorless oil (834 mg, 80%). 1H NMR (400 MHz, CDCl3) δ 3.36 (3H, s), 3.69–3.73 (1H, m), 3.74 (3H, s), 3.92–3.96 (1H, m), 3.99–4.03 (1H, m), and 7.80–7.81 (3H, m).

1. temperaturecooled
2. stirringthe mixture was stirred at room temperature for 20 minutes
3. stirringthe mixture was stirred at room temperature for 20 minutes
4. stirringthe mixture was stirred at room temperature for 30 minutes
5. extractionextracted with dichloromethane (2×40 mL)
6. dry with materialThe combined organic fractions were dried (MgSO4)
7. customthe solvent was evaporated under reduced pressure
8. customthe residue was purified by flash column chromatography on silica gel
9. washeluting with isohexane/EtOAc (90:10)