反应详情

To a round-bottom flask at room temperature was added (R)-methyl 1-(4-bromophenyl)-2,2-diphenylcyclopropanecarboxylate (17.9 mmol, 7.3 g, 1.0 equiv) in dry DMSO (35 mL). t-BuOK (39.6 mmol, 4.4 g, 2.2 equiv) was added in several portions over 30 minutes under argon. The reaction was monitored by TLC technique until the starting material was consumed completely. The reaction mixture was cooled with ice bath and acidified by saturated ammonium chloride aqueous (15 mL), followed by a slow addition of 1 N HCl (50 mL) with vigorous stirring until the pH value reached 3-4. Sticky solid precipitate was collected by filtration, washed with water (3×5 mL), dissolved in ethyl acetate (150 mL), washed with brine (3×10 mL), dried over anhydrous MgSO4, and concentrated in vacuo. The crude material was purified using flash column chromatography eluting with a 4:1 mixture of hexanes/ethyl acetate to provide the desired product as a white solid (4.9 g, 69% yield). Recrystallization in pentane/ethyl acetate (50/1) provided the enantioenriched product as a white solid (4.46 g, 64% yield, 99% ee). (S)-1-(4-bromophenyl)-2,2-diphenylcyclopropanecarboxylic acid was prepared by the same procedure,

1. customwas consumed completely
2. temperatureThe reaction mixture was cooled with ice bath
3. additionfollowed by a slow addition of 1 N HCl (50 mL)
4. filtrationSticky solid precipitate was collected by filtration
5. washwashed with water (3×5 mL)
6. dissolutiondissolved in ethyl acetate (150 mL)
7. washwashed with brine (3×10 mL)
8. dry with materialdried over anhydrous MgSO4
9. concentrationconcentrated in vacuo
10. customThe crude material was purified
11. washeluting with a 4:1 mixture of hexanes/ethyl acetate