Allyl bromide → (2S)-1,1-Diphenyl-2-Allyloxy-Pent-4-en

Temperatur

0 °C

(2S)-1,1-diphenyl-pent-4-en-2-ol 25a (0.37 g, 1.57 mmol) was dissolved in dry DMF (2 ml) and was added to a suspension of NaH (60% in mineral oil, 0.13 g, 3.14 mmol) in dry DMF (20 ml) at 0° C. The reaction mixture was allowed to reach room temperature over a period of 1 h. The reaction mixture was cooled again to 0° C. employing an ice-bath, and neat allyl bromide (0.57 g, 4.71 mmol) was added via syringe. The reaction mixture was removed from the ice-bath and stirred overnight at room temperature. The reaction was cooled again to 0° C. and quenched by slowly adding H2O (20 ml). The resulting mixture was extracted with Et2O (3×50 ml), and the combined organic phases were washed in turn with H2O, brine, and then dried over anhydrous Na2SO4. Filtration followed by concentration gave crude product as light orange oil. Purification by chromatography (hexane/ethyl ether=10:1) gave 0.37 g (2S)-1,1-Diphenyl-2-Allyloxy-Pent-4-en (85%, [α]D=(+)19.7, c=1, MeOH).

1. customThe reaction mixture was removed from the ice-bath
2. temperatureThe reaction was cooled again to 0° C.
3. customquenched by slowly adding H2O (20 ml)
4. extractionThe resulting mixture was extracted with Et2O (3×50 ml)
5. washthe combined organic phases were washed in turn with H2O, brine
6. dry with materialdried over anhydrous Na2SO4
7. filtrationFiltration
8. concentrationfollowed by concentration
9. customgave crude product as light orange oil
10. customPurification by chromatography (hexane/ethyl ether=10:1)

ORD-Eintrag

ord-222933ee42f242149579193adff36856

Quelldatensatz

uspto-grants-2011_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07915433B2