Imidazole → (S)-methyl 4-(tert-butyldimethylsilyloxy)-3,4-dihydro-2H-chromene-7-carboxylate

反応式

[CH3:1][O:2][C:3]([C:5]1[CH:14]=[C:13]2[C:8]([C@@H:9]([OH:15])[CH2:10][CH2:11][O:12]2)=[CH:7][CH:6]=1)=[O:4].N1C=CN=C1.[CH3:21][C:22]([Si:25](Cl)([CH3:27])[CH3:26])([CH3:24])[CH3:23]>CN(C=O)C>[Si:25]([O:15][C@@H:9]1[C:8]2[C:13](=[CH:14][C:5]([C:3]([O:2][CH3:1])=[O:4])=[CH:6][CH:7]=2)[O:12][CH2:11][CH2:10]1)([C:22]([CH3:24])([CH3:23])[CH3:21])([CH3:27])[CH3:26]

参加物

実験手順

A mixture of (S)-methyl-4-hydroxyl-3,4-dihydro-2H-chromene-7-carboxylate (10.2 g, 49.0 mmol), imidazole (3.70 g, 53.9 mmol), and TBSCl (8.12 g, 53.9 mmol) in DMF (100 mL) was stirred for 24 h at RT. The reaction mixture was quenched with H2O and extracted with ether (3×). The organic extracts were dried over MgSO4, and concentrated to give a brown oil. 1H NMR (400 MHz, CDCl3): δ 0.74 (s, 15H), 1.81 (m, 1H), 1.91 (m, 1H), 3.87 (s, 3H), 4.02 (m, 1H), 4.11 (m, 1H), 4.67 (t, 5.2 Hz, 1H), 7.09 (s, 1H), 7.11 (d, 7.6 Hz, 1H), 7.23 (d, 7.6 Hz, 1H).