2-fluoro-2-methylcyclopentane-1,3-dione

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

Procedure: A mixture of 2-methylcyclopentane-1,3-dione (4.50 g, 40.1 mmol) and Selectfluor (17.06 g, 48.2 mmol) in acetonitrile (80 mL) was heated to reflux for 2 h, cooled to room temperature and concentrated in vacuo. The residue was diluted with ethyl acetate (200 mL), washed with saturated sodium bicarbonate, water, brine, dried (MgSO4) and concentrated. Purification by silica gel chromatography, eluting with 20 to 50% ethyl acetate in hexanes, gave 2-fluoro-2-methylcyclopentane-1,3-dione (4.50 g, 82% yield). 1H NMR (400 MHz, chloroform-d) δ ppm 2.65-3.19 (4H, m), 1.38-1.77 (3H, m). was heated to reflux for 2 h concentrated in vacuo The residue was diluted with ethyl acetate (200 mL) washed with saturated sodium bicarbonate, water, brine dried (MgSO4) concentrated Purification by silica gel chromatography eluting with 20 to 50% ethyl acetate in hexanes