反应详情

温度

-78 °C

Stir a solution of (4-bromo-benzyloxy)-triisopropyl-silane (72 g, 209.7 mmol) and tetrahydrofuran (500 mL) at −78° C. Add a 1.6 M solution of n-butyllithium in hexanes (143 mL) over 10 min. After addition, allow the reaction mixture to reach −20° C. and stir for 5 minutes. Cool the reaction mixture to −78° C. In another flask, stir a solution of 3-cyanobenzaldehyde (25 g, 190.6 mmol) and tetrahydrofuran (250 mL) at −78° C. Add the lithium anion solution to the aldehyde solution via large cannula at a rate such that the internal aldehyde temperature does not rise above −50° C. After addition is complete, stir the reaction mixture 18 hours at room temperature. Dilute the reaction mixture with aqueous saturated ammonium chloride (500 mL) and ethyl acetate (200 mL). Separate the layers, and extract the aqueous layer with ethyl acetate (3×100 mL). Combine the organic layers, dry over anhydrous magnesium sulfate, filter, and concentrate. Purify the residue via silica gel chromatography eluting with hexanes to 9:1 hexanes:ethyl acetate to afford the title compound (56.1 g, 75%) as a colorless oil. LCMS (m/z) 396 M+1.

1. additionAfter addition
2. customto reach −20° C.
3. customdoes not rise above −50° C
4. additionAfter addition
5. stirringstir the reaction mixture 18 hours at room temperature
6. customSeparate the layers
7. extractionextract the aqueous layer with ethyl acetate (3×100 mL)
8. dry with materialCombine the organic layers, dry over anhydrous magnesium sulfate
9. filtrationfilter
10. concentrationconcentrate
11. customPurify the residue via silica gel chromatography
12. washeluting with hexanes to 9:1 hexanes