Reaktion #493733

Reaktionsgleichung

3-Bromo-2-methylpropene

sodium iodide

tert-butyl [(3S,5S,6R)-6-methyl-2-oxo-5-phenylpiperidin-3-yl]carbamate

Intermediate 9

tert-butyl [(3S,5S,6R)-6-methyl-2-oxo-5-phenylpiperidin-3-yl]carbamate

lithium bis(trimethylsilyl)amide

→

title compound

tert-Butyl [(3S,5S,6R)-6-methyl-1-(2-methylprop-2-en-1-yl)-2-oxo-5-phenylpiperidin-3-yl]carbamate

Lösungsmittel

water

tetrahydrofuran N-methyl-2-pyrrolidinone

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe resulting mixture was stirred at 0° C. for 2 h
2. 2
   Temperaturwarmed to 23° C.
3. 3
   workup.STIRRINGstirred for an additional 18 h
4. 4
   Extraktionextracted with ethyl acetate (3×)
5. 5
   WaschenThe combined organic extracts were washed with water, brine
6. 6
   Trocknendried over sodium sulfate
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated
9. 9
   SonstigePurification by silica gel chromatography (20% ethyl acetate→80% ethyl acetate/hexane)

Vorschrift

To a pre-cooled 0° C. solution of tert-butyl [(3S,5S,6R)-6-methyl-2-oxo-5-phenylpiperidin-3-yl]carbamate (described in Intermediate 9, step C, 0.20 g, 0.657 mmol) in tetrahydrofuran:N-methyl-2-pyrrolidinone (2:1, 4.0 mL) was added lithium bis(trimethylsilyl)amide (0.735 mL, 0.735 mmol, 1 M in THF) and the mixture was stirred at 0° C. for 10 min. 3-Bromo-2-methylpropene (0.31 mL, 3.29 mmol) and sodium iodide (0.098 g, 0.66 mmol) were added and the resulting mixture was stirred at 0° C. for 2 h and then warmed to 23° C. and stirred for an additional 18 h. The mixture was diluted with water and extracted with ethyl acetate (3×). The combined organic extracts were washed with water, brine, dried over sodium sulfate, filtered and concentrated. Purification by silica gel chromatography (20% ethyl acetate→80% ethyl acetate/hexane) afforded the title compound. MS: m/z=381.3 (M+Na).

Quelle