[CH2:1]([O:3][C:4](=[O:12])[C:5]([C:7]1[CH2:11][CH2:10][O:9][CH:8]=1)=[O:6])[CH3:2].[CH2:13]([OH:15])[CH3:14].[Br:16]N1C(=O)CCC1=O>ClCCl>[CH2:1]([O:3][C:4](=[O:12])[C:5]([C:7]1([Br:16])[CH2:11][CH2:10][O:9][CH:8]1[O:15][CH2:13][CH3:14])=[O:6])[CH3:2]Ethyl-2-(4,5-dihydrofuran-3-yl)-2-oxoacetate (VI, 100 g) was dissolved in dichloromethane (500 ml) and Ethanol (150 mL) was added. The reaction mass was cooled to 5 to 10° C. N-bromosuccinimide (115 g) was added lot wise by maintaining temp below 10° C. Reaction mass was then stirred at 20-30° C. till completion of reaction. Reaction mass was washed with sodium bicarbonate solution (2%, 3×400 mL) and the organic layer was used for the next step.
Wird geladen…