Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → Ethyl [2-(3-methoxyphenyl)-cyclohexylidene]acetate

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Reaction Steps

Combine 2-(3-methoxyphenyl)-cyclohexanone (5.0 g, 24.5 mmol), carbethoxymethylene triphenylphosphorane (15.4 g, 44.1 mmol), and toluene (150 mL), stir and heat at reflux. After 22 hours, cool to ambient temperature and concentrate under vacuum. Add ether and filter off the triphenylphosphine oxide precipitate and concentrate the ether filtrate. Flash chromatograph with 0% to 10% ethyl acetate/hexanes to yield the titled compound (6.71 g, 99%) as a clear oil. TLC Rf=0.58 in 8:1 hexanes:ethyl acetate. 1H NMR (CDCl3): 7.25 (m, 1H), 6.81-6.79 (m, 3H), 6.73 (s, 1H), 5.14 (s, 1H), 4.07 (q, J=14.4, 7.2, 2H), 3.80 (s, 3H), 3.80-3.69 (m, 1H), 3.39-3.36 (m, 1H), 2.20-2.16 (m, 1H), 2.06-2.03 (m, 1H), 1.96-1.87 (m, 3H), 1.65-1.54 (m, 2H), 1.2 (t, J=1.2, 8, 3H).

Provenance & Evidence