tert-butyl N-(2-oxopropyl)carbamate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of tert-butyl 2-(methoxy(methyl)amino)-2-oxoethylcarbamate (4.36 g, 0.02 mol) in THF (50 mL) added MeMgBr (40 ml, 0.08 ol) at −78° C. The formed mixture was stirred overnight. The mixture was quenched with NH4Cl and extracted with EtOAc. The organic phase was separated, dried over anhydrous Na2SO4, concentrated and purified by column chromatography to give tert-butyl 2-oxopropylcarbamate (2.5 g, 72%). 1H NMR (400 MHz, CDCl3): δ=1.42 (s, 9H), 2.18 (s, 3H), 4.01 (s, 2H), 5.22 (s, 1H). The mixture was quenched with NH4Cl extracted with EtOAc The organic phase was separated dried over anhydrous Na2SO4 concentrated purified by column chromatography

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of triethyl 2-fluoro-2-phosphonoacetate (1.07 mL, 5.2 mmol), tert-butyl (2-oxopropyl)carbamate (0.865 g, 5.0 mmol) and lithium hydroxide (0.21 g, 5.0 mmol) in THF (15 mL) was at room temperature for 16 hours. The mixture was cooled to 0° C. and lithium borohydride (0.22 g, 10.0 mmol) was added in portions. Stirring was continued at 0° C. for 1 hour and at room temperature for 2 hours. Saturated ammonium chloride solution (25 mL) was added to the mixture and the organic layer extracted with ethyl acetate (50 mL) and washed with brine (20 mL), dried over MgSO4, filtered and the solvent removed under reduced pressure to afford the crude product as a clear oil (0.90 g). Purification by flash chromatography eluting in 20% EtOAc in n-hexane afforded tert-butyl [(2E)-3-fluoro-4-hydroxy-2-methylbut-2-en-1-yl]carbamate (0.33 g, 30%) as white solid. 1H-NMR (400 MHz, CDCl3): δppm: 1.42 (9H, s), 1.68 (3H, d, J 3.2 Hz), 3.67 (2H, dd, J 6.4, 1.2 Hz), 3.80 (1H, t, J 6.4 Hz), 4.26 (2H, dd, J 24.8, 6.4 Hz), 4.98 (1H, brs). was continued at 0° C. for 1 hour and at room temperature for 2 hours the organic layer extracted with ethyl acetate (50 mL) washed with brine (20 mL) dried over MgSO4 filtered the solvent removed under reduced pressure to afford the crude product as a clear oil (0.90 g) Purification by flash chromatography eluting in 20% EtOAc in n-hexane