Reaktion #2338020

Reaktionsgleichung

Bromo-2-propenyl-magnesium

intermediate 2

3-fluoro-6,10b-dihydro-1aH-dibenzo-[3,4:6,7]cyclohept[1,2-b]oxirene

→

(trans)-2-fluoro-10,11-dihydro-11-(2-propenyl)-5H-dibenzo[a,d]cyclohepten-10-ol

Ausbeute 19.0%

(±)-trans-8-fluoro-10,11-dihydro-11-(2-propenyl)-5H-dibenzo[a,d]cyclo-hepten-10-ol

Ausbeute 36.0%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirred
2. 2
   Temperaturrefluxed for 2 hours
3. 3
   TemperaturThe reaction mixture was cooled on an ice-bath
4. 4
   Sonstigequenched with a 20% NH4Cl solution
5. 5
   Extraktionextracted with ethyl acetate
6. 6
   SonstigeThe organic layer was separated
7. 7
   Sonstigedried
8. 8
   Filtrationfiltered
9. 9
   Sonstigethe solvent was evaporated
10. 10
    SonstigeThe residue was purified
11. 11
    Sonstigeseparated into two regio-isomers by HPLC over silica gel (eluent: hexanes/ethyl acetate 9/1)
12. 12
    SonstigeTwo pure fraction groups were collected
13. 13
    Sonstigetheir solvent was evaporated

Vorschrift

Bromo-2-propenyl-magnesium (0.0542 mol) was added dropwise to a solution of intermediate 2 (0.04956 mol) in tetrahydrofuran (120 ml) under N2 atmosphere. The reaction mixture was stirred for 30 minutes at room temperature, then stirred and refluxed for 2 hours. The reaction mixture was cooled on an ice-bath, quenched with a 20% NH4Cl solution, and extracted with ethyl acetate. The organic layer was separated, dried, filtered and the solvent was evaporated. The residue was purified and separated into two regio-isomers by HPLC over silica gel (eluent: hexanes/ethyl acetate 9/1). Two pure fraction groups were collected and their solvent was evaporated, yielding 4.79 g (36%) of (±)-trans-8-fluoro-10,11-dihydro-11-(2-propenyl)-5H-dibenzo[a,d]cyclo-hepten-10-ol (intermediate 3) and 2.52 g (19%) of (trans)-2-fluoro-10,11-dihydro-11-(2-propenyl)-5H-dibenzo[a,d]cyclohepten-10-ol (intermediate 4).

Quelle