Sulfuric Acid → 4,4-Diethylcyclohex-2-en-1-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-ethylbutyraldehyde (12.3 mL, 100 mmol), methylvinylketone (5.6 mL, 67.3 mmol) and H2SO4 (0.07 mL) is stirred at 40° C. overnight. Another portion of methylvinylketone (5.6 mL, 67.3 mmol) and H2SO4 is added and stirring is continued at 40° C. for 2 d. The yellow solution is diluted with chloroform and the solvent is removed again under reduced pressure. The crude product is purified by vacuum distillation to give 4,4-diethyl-cyclohex-2-enone (10.7 g) as a colourless oil; Kp11 mbar=88° C.; 1H NMR (CDCl3): δ 6.71 (d, J=10.0 Hz, 1H), 5.92 (d, J=10.5 Hz, 1H), 2.42 (t, J=7.0 Hz, 2H), 1.84 (t, J=7.0 Hz, 2H), 1.57-1.40 (m, 4H), 0.87 (t, J=7.6 Hz, 6H).

Provenance & Evidence