tert-Butyl acrylate → Tert-butyl 4-(1,3-dioxoisoindolin-2-yl)-4-fluoro-4-ethoxycarbonylbutanoate

To a stirred solution of ethyl 2-(1,3-dioxoisoindolin-2-yl)-2-fluoroacetate (0.80 g, 3.2 mmol) in tetrahydrofuran (30 mL) is added lithium diisopropylamide (1.7 mL, 3.4 mmol, 2 M) at -78° C. After 30 minutes, t-butyl acrylate (0.42 g, 3.2 mmol) is added to the mixture which is allowed to reach room temperature. The solvent is removed in vacuo and the residue stirred with methylene chloride (50 mL) and water (30 mL) for 10 min. The organic layer is washed with brine (30 mL), and dried over sodium sulfate. The solvent is removed in vacuo to give tert-butyl 4-(1,3-dioxoisoindolin-2-yl)-4-fluoro-4-ethoxycarbonylbutanoate which is further purified by column chromatography.