反応 #581683

反応方程式

hexamethyldisilazane

n-butyllithium

hexane

1-bromo-3,3-dimethylbutane

compound

Methyl 2-(4-fluorophenyl)propanoate

lithium hexamethyldisilazide

→

product

収率 28.0%

Methyl 2-(4-fluorophenyl)-2,5,5-trimethylhexanoate

収率 28.0%

溶媒

tetrahydrofuran

tetrahydrofuran

反応条件

後処理

1. 1
   workup.STIRRINGby stirring at −78° C. for 30 min
2. 2
   その他The solution was quenched by addition of saturated ammonium chloride solution (4 mL)
3. 3
   濃縮concentrated in vacuo
4. 4
   workup.ADDITIONThe residue was diluted with ethyl acetate and water
5. 5
   抽出The organic layer was extracted with water (2×), saturated NaCl solution
6. 6
   乾燥dried (Na2SO4)
7. 7
   濃縮Concentration in vacuo
8. 8
   その他afforded an oil, which
9. 9
   workup.DISTILLATIONwas distilled under reduced pressure (90-93° C./0.3 mm Hg)

実験手順

A solution of the compound of Example 22A (11.75 g, 64.6 mmol) in tetrahydrofuran (30 mL) was added dropwise over 20 min to a −78° C. solution of lithium hexamethyldisilazide (previously prepared from hexamethyldisilazane (17.0 mL, 80.7 mmol) and n-butyllithium in hexane (2.5 M, 31.0 mL, 77.5 mmol)) in tetrahydrofuran (40 mL) and allowed to stir at that temperature for 1 h. The solution was then treated with 1-bromo-3,3-dimethylbutane (12.0 mL, 83.9 mmol), followed by stirring at −78° C. for 30 min, and then warming to 25° C. for 18 h. The solution was quenched by addition of saturated ammonium chloride solution (4 mL) and then concentrated in vacuo. The residue was diluted with ethyl acetate and water. The organic layer was extracted with water (2×), saturated NaCl solution and dried (Na2SO4). Concentration in vacuo afforded an oil, which was distilled under reduced pressure (90-93° C./0.3 mm Hg) to afford the product (4.85 g, 28%) as a colorless oil. 1H NMR (300 MHz, CDCl3): δ 0.86 (s, 9 H) 1.03 (m, 2 H) 1.51 (m, 3 H) 1.86 (m, 1 H) 2.00 (m, 1 H) 3.65 (m, 3H) 7.03 (m, 2 H) 7.27 (m, 2 H).

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