Reaktion #489966

Reaktionsgleichung

water

n-BuLi

6-Bromo-4,4-dimethyl-8-(propan-2-yl)-3,4-dihydro-2H-chromene

DMF

→

desired product

4,4-dimethyl-8-(propan-2-yl)-3,4-dihydro-2H-chromene-6-carbaldehyde

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to room temperature
2. 2
   workup.ADDITIONwas added
3. 3
   ExtraktionIt was then extracted with EtOAc (2×)
4. 4
   Trocknenthe combined organic layers were dried over Na2SO4
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated under vacuum
7. 7
   SonstigeThe crude residue was purified by silica gel chromatography
8. 8
   Wascheneluting with 0-10% EtOAc/Hexanes

Vorschrift

6-Bromo-4,4-dimethyl-8-(propan-2-yl)-3,4-dihydro-2H-chromene (154 mg, 0.54 mmol) in tetrahydrofuran (5.44 mL) was cooled to −78° C. and n-BuLi (261 μL, 0.65 mmol) was added dropwise via a syringe. The reaction mixture was stirred at −78° C. for 30 minutes, and then DMF (168 μL, 2.17 mmol) was added dropwise. The resulting mixture was allowed to warm to room temperature, and stirred for 30 minutes before water was added. It was then extracted with EtOAc (2×) and the combined organic layers were dried over Na2SO4, filtered, and concentrated under vacuum. The crude residue was purified by silica gel chromatography eluting with 0-10% EtOAc/Hexanes to obtain the desired product as a colorless oil.

Quelle