反応 #10843

反応方程式

5-Bromobenzaldehyde

2,3-dihydrofuran

cesium carbonate

→

3-(2,3-dihydro-furan-2-yl)-benzaldehyde

収率 40.0%

溶媒

dioxane

water

反応条件

後処理

1. 1
   その他Nitrogen was bubbled into the solution for 15 min
2. 2
   抽出extracted with ethyl acetate (3×20 mL)
3. 3
   乾燥The combined organic extracts were dried over sodium sulfate
4. 4
   濃縮concentrated to a brown oil

実験手順

Ex-119A: 5-Bromobenzaldehyde (0.5 g, 2.7 mmol) and 2,3-dihydrofuran (0.56 g, 8.1 mmol) were dissolved in dioxane (5.0 mL). Nitrogen was bubbled into the solution for 15 min followed by the sequential addition of cesium carbonate (0.96 g, 2.9 mmol) and bis(tri-t-butylphosphine)palladium(0) (0.014 g, 0.027 mmol). The solution was immediately heated to 45° C. and aged for 24 h. Upon completion, as determined by HPLC, the reaction was diluted with water (20 mL) and extracted with ethyl acetate (3×20 mL). The combined organic extracts were dried over sodium sulfate and concentrated to a brown oil. Silica gel chromatography (ethyl acetate/hexanes, 1:9) gave 0.18 g (40%) of 3-(2,3-dihydro-furan-2-yl)-benzaldehyde as a clear, colorless oil. 1H-NMR (300 MHz, CDCl3) δ 10.03 (s, 1H), 7.88 (s, 1H), 7.82 (d, 1H, J=7.2 Hz), 7.62–7.64 (m, 1H), 7.53 (t, 1H, J=7.2 Hz), 6.48 (q, 1H, J=Hz), 5.60 (dd, 1H, J=8.1, 10.8 Hz), 4.98 (q, 1H, J=3.3 Hz), 3.15 (ddt, 1H, J=15.0, 8.1, 2.5 Hz), 2.59 (ddt, 1H, J=15.0, 8.1, 2.5 Hz). MS (EI) m/z=174 ([M]+, 100%). HRMS (EI) Calcd. for C11H10O2: 174.0681. Found: 174.0677.

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