[C:1]([O:7][CH2:8][CH3:9])(=[O:6])[CH2:2][C:3]([CH3:5])=[O:4].[H-].[Na+].Cl[CH2:13][CH:14]=[C:15]([CH3:17])[CH3:16]>CN(C)C=O>[CH2:8]([O:7][C:1](=[O:6])[CH:2]([C:3](=[O:4])[CH3:5])[CH2:13][CH:14]=[C:15]([CH3:17])[CH3:16])[CH3:9]To a solution of 26.05 g ethyl acetoacetate in 150 ml of dimethylformamide, 8.30 g 60% sodium hydride were added portionwise over 1 hour while the temperature rose to 60° C. After cooling down to room temperature, a solution of 24.8 g 1-chloro-3-methyl-2-butene in 50 ml of dimethylformamide was dropped in. Then the mixture was stirred at room temperature for 2.5 hours. The mixture was quenched with water and extracted with ether. The combined organic phase was dried, filtered and evaporated to dryness. The resulting yellow oil was purified by distillation to yield 23.16 g of a colourless oil.
読み込み中…