Sodium hydride → HCID 86637444, compound

Participants

Reaction Conditions

Reaction Steps

A slurry of 60% sodium hydride suspension in mineral oil (0.80 g, 20.4 mmol) in tetrahydrofuran (28 mL) is cooled at 0° C. under a nitrogen atmosphere. A solution of substantially optically pure (S)-4-(2,2-difluoro-vinyl)-pyrrolidin-2-one (IIIb) (2 g, 13.6 mmol) in tetrahydrofuran (8 mL) is added over a 30 minutes period. The reaction mixture is stirred 10 minutes at 0° C. then a solution of 2-bromo-butyric acid methyl ester (V) (3.20 g, 17.6 mmol) in tetrahydrofuran (2 mL) is added over a 15 minutes period. The reaction mixture is stirred at 0° C. for 4.5 h then the reaction mixture is allowed to warm to room temperature and diluted with water (15 mL). Tetrahydrofuran is removed by evaporation and the residue is extracted with isopropyl acetate (2×10 mL). The combined organic layers are dried over anhydrous magnesium sulfate and evaporated to afford 3 g (12.1 mmol, 89%) of compound (VIb), as a mixture respectively of epimer (VIba) and epimer (VIbb).

Provenance & Evidence