Bromide ion → 1-[4-(4-Chlorophenyl)-cyclohexyl]pent-4-en-1-one

Participants

Reaction Conditions

Reaction Steps

While under a nitrogen atmosphere, a solution of 4-(4-chlorophenyl)-cyclohexanecarboxylic acid, methoxy-methyl amide (1.8 g, 6.39 mmol), in tetrahydrofuran (10 mL) was cooled to 0° C. and treated with 4-butenylmagnesiun bromide (0.5 M in THF, 31.95 mL, 15.98 mmol) dropwise. After stirring for 1 hour at 0° C. the reaction mixture was warmed to room temperature overnight, poured into water, acidified to pH 3-4 with 1 N hydrochloric acid and extracted with ethyl acetate (3×). The combined organic phase was washed with saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. Purification by flash column chromatography (silica gel, 0-20% ethyl acetate in heptane) gave 1-[4-(4-chlorophenyl)-cyclohexyl]pent-4-en-1-one as a colorless oil (1.62 g, 92%); 1H NMR (CDCl3, 300 MHz) δ 7.26 (m, 2H), 7.12 (d, J=8 Hz, 2H), 5.81 (m, 1H), 5.02 (m, 2H), 2.58 (t, J=7 Hz, 2H), 2.44 (m, 2H), 2.34 (m, 2H), 1.99 (m, 4H) and 1.47 (m, 4H).

Provenance & Evidence