(S)-2-(Boc-amino)-3-cyclohexyl-N-methoxy-N-methylpropanamide → (S)-tert-butyl 1-cyclohexyl-3-oxopentan-2-ylcarbamate
Reaction equation
[CH:1]1([CH2:7][C@H:8]([NH:15][C:16](=[O:22])[O:17][C:18]([CH3:21])([CH3:20])[CH3:19])[C:9](N(OC)C)=[O:10])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[CH3:23][CH2:24][Mg+].[Br-]>C1(C)C=CC=CC=1>[CH:1]1([CH2:7][C@H:8]([NH:15][C:16](=[O:22])[O:17][C:18]([CH3:19])([CH3:20])[CH3:21])[C:9](=[O:10])[CH2:23][CH3:24])[CH2:2][CH2:3][CH2:4][CH2:5][CH2:6]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
To a solution of (S)-tert-butyl 3-cyclohexyl-1-(methoxy(methyl)amino)-1-oxopropan-2-ylcarbamate (5.23 g, 16.66 mmol) in anhydrous toluene (80 mL) at −20° C. was added EtMgBr (3 M in Et2O, 16.7 mL, 49.97 mmol) slowly. The reaction was allowed to warm to 0° C., and stirred at this temperature for 2 h. The reaction was quenched with 1 M HCl at 0° C. and extracted with EtOAc. The organic phase was washed with sat. aq. NaHCO3, brine, concentrated to give (S)-tert-butyl 1-cyclohexyl-3-oxopentan-2-ylcarbamate. The product was used in the next step without further purification. MS ESI +ve m/z 306 (M+Na).