反应详情

4-Chloro-2-methyl-2-butane (15.5 mL, 14.4 g, 137.5 mmol) was added dropwise to stirred magnesium turnings (6.75 g, 225 mmol) in anhydrous THF (465 mL) under argon at 0° C. The stirring was continued 0° C. for 1 hour. The cooling bath was removed, and the mixture was stirred at room temperature for an additional 1.5 hours. The mixture was then cooled to −78° C. and the formed Grignard reagent was added via cannula to a solution of tosylate 4 (10 g, 27.5 mmol) in anhydrous THF (70 mL). Li2CuCl4 (160mL) [previously prepared from LiCl (1.36 g, 32.1 mmol) and CuCl2 (2.17 g, 16.1 mmol)] was then added to the reaction mixture. The cooling bath was removed, and the reaction was stirred at room temperature for 17 hours. The mixture was extracted with CH2Cl2, and the organic layer was washed with NH4Cl and NaHCO3, dried over Na2SO4, and evaporated. The residue was chromatographed on silica gel using hexane/EtOAc (7:3) as an eluent to give oily product 5 (5.65 g, 78%).

1. customThe cooling bath was removed
2. temperatureThe mixture was then cooled to −78° C.
3. additionwas then added to the reaction mixture
4. customThe cooling bath was removed
5. stirringthe reaction was stirred at room temperature for 17 hours
6. extractionThe mixture was extracted with CH2Cl2
7. washthe organic layer was washed with NH4Cl and NaHCO3
8. dry with materialdried over Na2SO4
9. customevaporated
10. customThe residue was chromatographed on silica gel