Reaktion #87111

Reaktionsgleichung

(S)-tert-butyl (3-cyclohexyl-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate

isopropenylmagnesium bromide

→

(S)-tert-butyl (1-cyclohexyl-4-methyl-3-oxopent-4-en-2-yl)carbamate

Ausbeute 49.0%

Lösungsmittel

THF

methyl-THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas quenched with heptane/citric acid (1:1)
2. 2
   ExtraktionThe product was extracted with EtOAc (2×)
3. 3
   Waschenwashed with brine
4. 4
   Trocknendried with sodium sulfate
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated
7. 7
   SonstigeThe crude product was triturated from cold (0° C.) methanol

Vorschrift

To (S)-tert-butyl (3-cyclohexyl-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate (12.2 g, 38.9 mmol) in THF (150 mL) at 0° C. was added isopropenylmagnesium bromide (71.2 mL of a 1.5 N solution in methyl-THF, 0.107 mol) dropwise. After stirring at 0° C. for 2 h the mixture was quenched with heptane/citric acid (1:1). The product was extracted with EtOAc (2×), washed with brine, dried with sodium sulfate, filtered, and concentrated. The crude product was triturated from cold (0° C.) methanol to provide (S)-tert-butyl (1-cyclohexyl-4-methyl-3-oxopent-4-en-2-yl)carbamate (5.36 g, 49%) as a colorless crystalline solid. MS (EI) for C17H29NO3, found 196.2 [M-Boc]+.

Quelle