反应详情

Sodium hydride (0.3965 g, 16.52 mmol) was added slowly to a NaCl ice bath containing EtOH (5.6 mL, 2.6 M) stirring under N2. 59 (2.2727 g, 14.01 mmol) and diethyloxalate (2.0649 g, 14.13 mmol) were mixed together, and then added to the chilled NaOEt solution. After stirring for 5 minutes, the reaction was warmed to room temperature. After stirring for 5 h, the reaction was quenched at 0° C. with 1N HCl and extracted 2× with CH2Cl2. The combined organics were washed with H2O, dried with Na2SO4, filtered, concentrated, and purified by silica gel chromatography (Combiflash column, 67:30:3 Hexanes: CH2Cl2: 2N NH3 in EtOH): Only pure fractions were combined and concentrated to obtain 60. 1H (CDCl3, 400 MHz): δ 14.55 (1H, broad s), 7.32-7.12 (5H, m), 6.36 (1H, s), 4.33 (2H, q, J=7.0 Hz), 3.05 (1H, dd, J=13.5, 6.8 Hz), 2.84 (1H, app sex, J=7.0 Hz), 2.67 (1H, dd, J=13.5, 7.8 Hz), 1.36 (3H, t, J=7.1 Hz), 2.33 (3H, d, J=7.0 Hz) ppm. 13C (CDCl3, 100 MHz): δ 205.78, 166.96, 161.88, 138.75, 128.80, 128.30, 126.29, 100.75, 62.32, 46.35, 39.10, 16.51, 13.88 ppm. DEPT (CDCl3, 100 MHz): CH3 carbons: 16.51, 13.88; CH2 carbons: 62.32, 39.10; CH carbons: 128.80, 128.30, 126.29, 100.75, 46.35 ppm. HPLC: 11.084 min.

1. stirringAfter stirring for 5 minutes
2. stirringAfter stirring for 5 h
3. customthe reaction was quenched at 0° C. with 1N HCl
4. extractionextracted 2× with CH2Cl2
5. washThe combined organics were washed with H2O
6. dry with materialdried with Na2SO4
7. filtrationfiltered
8. concentrationconcentrated
9. custompurified by silica gel chromatography (Combiflash column, 67:30:3 Hexanes: CH2Cl2: 2N NH3 in EtOH)
10. concentrationconcentrated