Propanal → 1,3-Diphenylhexane-1,4-dione

Participants

Reaction Conditions

Reaction Steps

A mixture of (E)-1,3-diphenyl-propenone (1.042 g; 5.00 mmol), propionaldehyde (0.40 mL; 5.6 mmol), 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide (126 mg; 0.500 mmol) and triethyl-amine (0.42 mL; 3.0 mmol) in absolute ethanol (3.0 mL) was degassed then heated at 70° C. for 25 h. After an additional 1.5 h at 80° C., the organic volatiles were removed on a rotary evaporator. EtOAc (25 mL) was added and the solution washed with water (3×5 mL) and satd NaCl (2×5 mL); then dried (MgSO4), filtered through silica and washed through with EtOAc. Crude product was adsorbed onto silica (2.0 g) then purified by MPLC (40 g of silica using a 0→20% EtOAc in hexanes gradient). Pure product was obtained as a clear, pale tan liquid (760 mg; 57%). 1H NMR (CDCl3) δ 7.96 (m, 2H), 7.56 (m, 1H), 7.45 (m, 2H), 7.38-7.26 (m, 5H), 4.43 (dd, J=3.4, 10.2 Hz, 1H), 4.05 (dd, J=10.4, 18.0 Hz, 1H), 3.14 (dd, J=3.8, 18.2 Hz, 1H), 2.65 (m, 1H), 2.53 (m, 1H), 1.02 (t(app), J=7.2 Hz, 3H).

Provenance & Evidence