反应详情

温度

-35 °C

The following experimental procedure is representative of the reactions set forth below in Table III. The organocalcium reagent (2.66 mmol) was prepared from 1-chlorooctane (395 mg, 2.66 mmol) and highly reactive calcium (3.10 mmol) as described above. An organocalcium cuprate reagent was prepared by adding lithium 2-thienylcyanocuprate (Aldrich Chemical Co., Milwaukee, Wis., 0.25M in THF, 14 mL, 3.50 mmol) to the calcium reagent via a syringe at -50° C. The reaction mixture was gradually warmed to -35° C. over a 30 minute period. The reaction mixture was cooled to -50° C. and 2-cyclohexen-1-one (210 mg, 2.18 mmol) was added via a disposable syringe. The resulting mixture was gradually warmed to room temperature. Saturated aqueous NH4Cl solution (20 mL) was added at room temperature. The reaction mixture was then filtered through a small pad of Celite™ filter agent and was washed with Et2O (50 mL). The aqueous layer was extracted with Et2O (2×30 mL). The combined organic phases were washed with H2O (3×15 mL) and dried over anhydrous MgSO4. Removal of solvent and flash-column chromatography on silica gel (70 g, 230-400 mesh, eluted sequentially with 50:1 hexanes/EtOAc and 10:1 hexanes/EtOAc) gave 3-octylcyclohexanone (401 mg, 87% yield): IR (neat) 2954, 2925, 2854, 1714, 1458, 1225 cm-1 ; 1H NMR (200 MHz, CDCl3) δ 1.10-2.50 (m, 23 H), 0.88 (t, J=6.4 Hz, 3 H); 13C NMR (50 MHz, CDCl3) δ 212.0, 48.2, 41.5, 39.1, 36.6, 31.8, 31.3, 29.7, 29.5, 29.2, 26.6, 25.3, 22.6, 14.1.

1. customAn organocalcium cuprate reagent was prepared
2. temperatureThe reaction mixture was cooled to -50° C.
3. temperatureThe resulting mixture was gradually warmed to room temperature
4. filtrationThe reaction mixture was then filtered through a small pad of Celite™
5. filtrationfilter agent
6. washwas washed with Et2O (50 mL)
7. extractionThe aqueous layer was extracted with Et2O (2×30 mL)
8. washThe combined organic phases were washed with H2O (3×15 mL)
9. dry with materialdried over anhydrous MgSO4
10. customRemoval of solvent and flash-column chromatography on silica gel (70 g, 230-400 mesh
11. washeluted sequentially with 50:1 hexanes/EtOAc and 10:1 hexanes/EtOAc)