反应详情

温度

-78 °C

Sodium trimethylsilylamide 1M in THF (20.73 mL, 20.73 mmol) was added to a 2-neck round bottom flask under nitrogen. The flask was placed in an acetone bath cooled to about −78° C. A solution of methyl 2-methoxyacetate (2.34 mL, 23.55 mmol) and 3-benzyloxybenzaldehyde (4.0 g, 18.85 mmol) in dry THF (24 mL) was added dropwise via cannula over 10 minutes. The mixture was stirred at −78° C. for 3 hours. HPLC-MS showed the presence of starting aldehyde at this time. Additional 10 mL of NaHDMS were added, and the mixture was stirred for another hour, and then HCl 3N (50 mL) was added to the mixture at −78° C. The bath was removed, and the mixture was extracted with diethyl ether (4×50 mL). The combined organic layers were dried over MgSO4 and concentrated to afford an oil that was purified by chromatography (silica gel, hexanes/ethyl acetate 3:1). Rf. 0.13. (two isomers) 1H-NMR (CDCl3, 200.15 MHz): 7.45–7.22 (m, 12H), 7.05–6.89 (m, 6H), 5.07 (d, 4H, J=1.1), 4.93 (dd, 2H, J=11.8, 5.9), 3.97 (d, 1H, J=5.6), 3.89 (d, 1H, J=5.4), 3.67 (s, 3H), 3.65 (s, 3H), 3.40 (s, 3H), 3.37 (s, 3H), 2.92 (br s, 1H), 2.83 (br s, 1H).

1. customThe flask was placed in an acetone bath
2. additionAdditional 10 mL of NaHDMS were added
3. stirringthe mixture was stirred for another hour
4. customThe bath was removed
5. extractionthe mixture was extracted with diethyl ether (4×50 mL)
6. dry with materialThe combined organic layers were dried over MgSO4
7. concentrationconcentrated
8. customto afford an oil that
9. customwas purified by chromatography (silica gel, hexanes/ethyl acetate 3:1)