反应详情

温度

-78 °C

A solution of LDA (34.9 mL, 52.4 mmol, 1.5M in cyclohexane) in anhydrous THF (60 mL) was cooled to −78° C. in a dry ice/acetone bath and added to a solution of 2-o-Tolyloxy-propionic acid ethyl ester in anhydrous THF (60 mL) also cooled to −78° C. under an atmosphere of nitrogen. After five minutes, 4-benzyloxybenzaldehyde (5.56 g, 26.2 mmol) was added in one portion. After stirring for one minute, the reaction mixture was quenched with acetic acid (5 mL, 87.4 mmol, d=1.049) and a saturated solution of aqueous NH4Cl (50 mL). The biphasic mixture was allowed to warm to room temperature and diluted with diethyl ether (1 L). The organic layer was washed with water, dried over MgSO4, and concentrated in vacuo. The residue was purified by flash column chromatography (13% ethyl acetate in hexanes) to provide a mixture of diastereomers of the titled compound (6.36 g, 54%). 1H NMR (400 MHz, CDCl3): • 7.44-7.32 (m, 6H), 7.16-6.82 (m, 5H), 69.74-6.66 (m, 2H), 5.16 (d, 1H, J=3.52 Hz), 5.07 (s, 2H), 4.26-4.15 (m, 2H), 2.28 (s, 3H), 1.43 (s, 3H), 1.22-1.17 (m, 3H). Rf=0.25 in 25% ethyl acetate in hexanes.

1. temperatureto warm to room temperature
2. washThe organic layer was washed with water
3. dry with materialdried over MgSO4
4. concentrationconcentrated in vacuo
5. customThe residue was purified by flash column chromatography (13% ethyl acetate in hexanes)
6. customto provide