O[CH:2]1[CH:5]([C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[Cl:12])[N:4]([C:13]2[CH:18]=[CH:17][C:16]([O:19][CH3:20])=[CH:15][CH:14]=2)[C:3]1=[O:21].[H-].[Na+].[C:24](Cl)(=[O:27])[CH:25]=[CH2:26]>C(Cl)Cl>[C:24]([CH:2]1[CH:5]([C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[Cl:12])[N:4]([C:13]2[CH:18]=[CH:17][C:16]([O:19][CH3:20])=[CH:15][CH:14]=2)[C:3]1=[O:21])(=[O:27])[CH:25]=[CH2:26]To a solution of C3-hydroxy β-lactam 24 (5.80 g, 19.1 mmol) in 30 ml of freshly distilled CH2Cl2 was added NaH (60% suspension in mineral oil, 0.83 g, 21.0 mmol), and the mixture was stirred for 15 min at room temperature. Acryloyl chloride (2.59 g, 28.64 mmol) was then added dropwise and the resultant mixture was stirred until TLC indicated the disappearance of starting material. The reaction was quenched with a 5% solution of NH4Cl and extracted (3×20 ml) with CH2Cl2. The combined organic layers were dried over anhydrous MgSO4 and purified with column chromatography on silica gel (1:4, EtOAc:hexanes) to give 4.92 g (72%) of 25 as a white solid, mp 99-100° C. 1H NMR (250 MHz) δ 7.33 (d, J=7.9 Hz, 1H), 7.23-7.10 (m, 5H), 6.75 (d, J=8.9 Hz, 2H), 6.17 (d, J=5.0 Hz, 1H), 5.98 (dd, J=16.9, 1.00 Hz, 1H), 5.74 (dd, J=16.9, 10.4 Hz, 1H), 5.69 (d, J=5.0 Hz, 1H), 5.59 (d, J=10.4, 1.0 Hz, 1H), 3.66 (s, 3H). 13C NMR (63 MHz) δ 163.6, 161.2, 156.6, 133.7, 132.3, 130.3, 130.1, 129.8, 128.5, 126.8, 126.5, 118.6, 114.4, 75.3, 61.3, 58.2, 55.3.
Wird geladen…
