[H-].[Na+].[C:3]([O:9][CH3:10])(=[O:8])[CH2:4][C:5]([CH3:7])=[O:6].N[C@H](C(O)=O)CC1C=C2C(C=CC=C2)=CC=1.Br[CH2:28][CH2:29][O:30][CH2:31][C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1>COCCOC>[CH3:10][O:9][C:3](=[O:8])[CH:4]([CH2:28][CH2:29][O:30][CH2:31][C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1)[C:5](=[O:6])[CH3:7]To a suspension of NaH (2.0 g, 60% in mineral oil) in DME (50 ml) at 0° C. is added dropwise a solution of methyl acetoacetate (5.8 g, 50 mmol) in DME (10 mL). The solution is stirred at room temperature for 30 minutes. Nal (7.5 g) is added in one portion and then benzyl bromoethyl ether (10.7 5 g, 50 mmol). The mixture is stirred at 70–80° C. overnight. After the formed solid is removed, the solvent is removed. The residue is purified by column with 4:1 of hexane to ethyl acetate to a colorless oil (159).
Wird geladen…