Acetone → 5-(4-Bromo-2-ethylphenyl)-4-hydroxycyclopent-2-enone
Reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]([C:10]2[O:11][CH:12]=[CH:13][CH:14]=2)O)=[C:4]([CH2:15][CH3:16])[CH:3]=1.CC(C)=[O:19]>O>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[C:12](=[O:11])[CH:13]=[CH:14][CH:10]2[OH:19])=[C:4]([CH2:15][CH3:16])[CH:3]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of (4-bromo-2-ethylphenyl)furan-2-yl-methanol (13.6 g, 0.039 mol) in acetone (300 ml) and water (30 ml) at 55° C. is added polyphosphoric acid (5.0 g, 0.05 mol). After stirring at this temperature for 20 hours the reaction mixture is cooled to room temperature then concentrated in vacuo. The crude product is then partitioned between ethyl acetate (200 ml) and water (200 ml), and the organic phase is separated. After drying over anhydrous magnesium sulfate, all solvents are removed and the crude product is purified by flash column chromatography (1:1 ethyl acetate/hexane) to afford 5-(4-bromo-2-ethylphenyl)-4-hydroxycyclopent-2-enone as a brown gum.