Reaktion #421071

Reaktionsgleichung

(S)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-oxopropyl)-6-phenyl-1,3-oxazinan-2-one

methylmagnesium bromide

→

(S)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-hydroxy-2-methylpropyl)-6-phenyl-1,3-oxazinan-2-one

Ausbeute 65.0%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe reaction mixture was quenched with aq NaHCO3 (50 mL) under ice water bath
2. 2
   SonstigeThe organic layers were separated
3. 3
   ExtraktionThe aqueous layer was extracted with EtOAc (150 mL)
4. 4
   WaschenThe combined organic layers were washed with brine
5. 5
   Trocknendried over Na2SO4
6. 6
   Einengenconcentrated in vacuo
7. 7
   Sonstigeto give the crude product, which
8. 8
   Sonstigewas purified column chromatography (petroleum ether/EtOAc=5:1 to 2:1)

Vorschrift

To a solution of (S)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-oxopropyl)-6-phenyl-1,3-oxazinan-2-one (20 g, 46.4 mmol) in anhydrous THF (200 mL) was added dropwise methylmagnesium bromide (31 mL, 144 mmol) at −78° C. under nitrogen. Then the mixture was stirred at rt for 1 h. The reaction mixture was quenched with aq NaHCO3 (50 mL) under ice water bath. The organic layers were separated. The aqueous layer was extracted with EtOAc (150 mL). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated in vacuo to give the crude product, which was purified column chromatography (petroleum ether/EtOAc=5:1 to 2:1) to afford (S)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-hydroxy-2-methylpropyl)-6-phenyl-1,3-oxazinan-2-one (13 g, 65%). After re-crystallization from EtOH, 4 g of the pure compound was obtained. 1H NMR (CDCl3): 1.06 (s, 3H), 1.12 (s, 3H), 1.44 (d, 3H), 2.14 (m, 3H), 2.21 (m, 1H), 2.33 (m, 1H), 2.76 (m, 1H), 5.54 (q, 1H), 6.74 (d, 2H), 7.16 (d, 2H), 7.28 (m, 5H).

Quelle