Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → Ethyl-3-(5'-fluoro-2'-methoxyphenyl)acrylate

Participants

Reaction Steps

To a solution of 5-fluoro-2-methoxybenzaldehyde (4.3 g, 28.0 mmol) in dry CH2Cl2 (30 mL) at 0° C. was added carbethoxymethylenetriphenylphosphorane (10.7 g, 30.1 mmol) portion-wise and the reaction was warmed to room temperature and stirred for 12 h. The solvent was then removed in vacuo and the residue was purified by flash column chromatography (EtOAc/hexane, 10:90, v:v, Rf=0.2) to yield the product (6.0 g, 95%) as a 4:1 mixture of trans:cis diastereomers; 1H NMR (CDCl3, 500 MHz): δ 7.93 (d, J=16.2 Hz, 0.8 H), 7.33 (dd, J=3.1, 9.2 Hz, 0.2 H), 7.21 (dd, J=3.1, 9.2, Hz, 0.8 H), 7.08 (d, J=12.5 Hz, 0.2 H), 7.03 (dt, J=3.0, 8.8 Hz, 0.8 H), 6.99 (dt, J=3.0, 8.8 Hz, 0.2 H), 6.84 (dd, J=3.1, 8.6 Hz, 0.8 H), 6.79 (dd, J=3.3, 9.1 Hz, 0.2 H), 6.47 (d, J=16.2 Hz, 0.8 H), 5.99 (d, J=12.5 hz, 0.2 H), 4.25 (q, J=7.1 Hz, 1.6 H), 4.15 (q, J=7.0 Hz, 0.4 H), 3.86 (s, 2.4H), 3.81 (s, 0.6 H), 1.34 (t, J=7.1 Hz, 2.4 H), 1.22 (t, J=7.0 Hz, 0.6 H).

Provenance & Evidence