反应详情

To a solution of BF3.OEt2 (0.350 mL, 2.50 mmol) and ethyl diazoacetate (0.390 mL, 3.42 mmol) was added a solution of 4-methyl-tetrahydro-pyran-4-carboxaldehyde (350 mg, 2.73 mmol) in CH2Cl2 (15 mL). After 20 min, the mixture was poured into half-saturated aq. NaCl and extracted with CH2Cl2. The combined organic layers were dried and concentrated. Chromatography (EtOAc/hexanes) afforded the title compound (461 mg, 79%) as a colorless oil. MS (ESI): mass calcd. for C11H18O4, 214.1; m/z found, 215.2 [M+H]+. 1H NMR (mixture of tautomers; CDCl3): 12.5 (s, 0.5H), 5.05 (s, 0.5H), 4.25-4.17 (m, 2H), 3.76-3.53 (m, 2H), 5.52 (s, 3H), 2.05-1.92 (m, 2H), 1.56-1.47 (m, 2H), 1.26-1.22 (m, 3H), 1.38-1.34 (m, 3H).

1. extractionextracted with CH2Cl2
2. customThe combined organic layers were dried
3. concentrationconcentrated