To a solution of trimethyl phosphonoacetate (412 mg, 2.26 mmol) in THF (15 mL) at 0° C. was added 1M sodium bis(trimethylsilyl)amide in THF (2.26 mL, 2.26 mmol) dropwise. After stirring 15 min the mixture was cooled to −78° C. and a solution of aldehyde (4) (625 mg, 1.89 mmol) in THF (8 mL) was added dropwise. The solution was allowed to warm to rt. After stirring 4 h, brine was added and the mixture was extracted with EtOAc. The combined organic layers were washed with water, brine, and dried (MgSO4). The solvent was removed under reduced pressure and the residue was chromatographed (silica gel, 7.5 to 15% EtOAc/hexanes) to give the ester (5) as a white solid (658 mg, 90%): 1 H NMR (CDCl3) δ 7.52 (d, J=16.1 Hz, 1 H), 7.15 (m, 11 H), 6.86 (d, J=8.1 Hz, 2 H), 6.28 (d, J=16.1 Hz, 1 H), 3.76 (s, 3 H), 2.47 (q, J=7.7 Hz, 2 H), 0.93 (t, J=7.7 Hz, 3 H); APcI m/z: 428 (M+H+CH3CN+, 100%).
