[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[C:5]([O:9][CH3:10])[C:4]=1[C:11](=O)[CH2:12][C:13]([CH3:20])([CH3:19])[CH2:14][C:15](OC)=[O:16].C([O-])(=O)C.[NH4+].[BH3-]C#[N:29].[Na+].Cl>CO>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][CH:6]=[C:5]([O:9][CH3:10])[C:4]=1[CH:11]1[NH:29][C:15](=[O:16])[CH2:14][C:13]([CH3:20])([CH3:19])[CH2:12]1
A sealed tube containing a mixture of methyl 5-(2,6-dimethoxyphenyl)-3,3-dimethyl-5-oxopentanoate (474 mg; 1.61 mmol), ammonium acetate (1.241 g; 16.10 mmol), and NaBH3CN (106 mg; 1.61 mmol) in anh. MeOH (8 ml) was heated to 80° C. for 48 h. After cooling to rt, 2 M aq. HCl (7.5 ml) was added, and the volatiles were removed under reduced pressure. The resulting aq. layer was extracted with DCM (3×20 ml), and the mixed organic layers were dried over anh. MgSO4, filtered, and concentrated to dryness under reduced pressure. Purification by FC (DCM/MeOH=25/1) afforded 6-(2,6-dimethoxyphenyl)-4,4-dimethylpiperidin-2-one as a yellow solid. LC-MS (conditions D): tR=0.91 min.; [M+H]+: 264.22 g/mol.
Wird geladen…
