反应 #1244302

反应方程式

methyl 4-bromomethylbenzoate

cyclooctanone

LDA

→

desired product

收率 80.2%

4-(2-Oxo-cyclooctylmethyl)benzoic acid methyl ester

收率 80.2%

溶剂

THF

THF

反应条件

后处理

1. 1
   workup.WAITAfter 30 min
2. 2
   其他the reaction was quenched with H2O (10 mL)
3. 3
   其他the THF was removed on a rotary evaporator
4. 4
   workup.ADDITIONThe residue was diluted with EtOAc (100 mL)
5. 5
   洗涤washed with H2O (3×100 mL) and brine (1×50 mL)
6. 6
   干燥dried over MgSO4

实验过程

To a stirring solution of cyclooctanone (1.76 g, 14.0 mmol) in THF (30 mL) at −78° C. was added LDA (8.54 mL, 15.4 mmol, 1.8 M in heptane/THF/ethylbenzene). After 1 h, a solution of methyl 4-bromomethylbenzoate (3.53 g, 15.4 mmol) in THF (10 mL) was added and the reaction mixture was allowed to warm to rt. After 30 min, the reaction was quenched with H2O (10 mL) and the THF was removed on a rotary evaporator. The residue was diluted with EtOAc (100 mL), washed with H2O (3×100 mL) and brine (1×50 mL), and dried over MgSO4. Chromatography of the crude product (50:1 to 9:1 hexanes/EtOAc) yielded the desired product as a colorless oil (3.08 g, 80%, Rf=0.30, 9:1 hexanes/EtOAc). IR: 3426, 2929, 2856, 1721, 1700, 1657, 1611 cm−1. 1H NMR (CDCl3, 300 MHz): δ 1.10-1.28 (m, 1H), 1.28-1.42 (m, 1H), 1.42-1.80 (m, 6H), 1.80-1.90 (m, 1H), 1.90-2.08 (m, 1H), 2.08-2.18 (m, 1H), 2.22-2.35 (m, 1H), 2.64 (dd, 1H, J=12.6, 6.0 Hz), 3.01 (m, 2H), 3.89 (s, 3H), 7.20 (d, 2H, J=8.1 Hz), 7.93 (d, 2H, J=8.4 Hz). 13C NMR (CDCl3, 75 MHz): δ 24.5, 24.6, 25.1, 27.7, 32.9, 38.1, 43.2, 51.5, 52.0, 128.1, 129.0, 129.7, 145.6, 167.0, 218.9. FAB—HRMS: Calcd. for C17H23O3+ [M+H]+: 275.1647, found: 275.1648.

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