Citric Acid → 1,1-Dimethylethyl 3,3-dimethyl-2-oxo-1-piperidinecarboxylate

Participants

Reaction Conditions

Reaction Steps

To the title compound of Step (A) (1.08 g, 5.42 mmol) in 10.8 ml THF at -78° C., lithium bis(trimethylsilyl)amide (1M in THF, 13.6 ml, 13.6 mmol) was added dropwise in 10 min. The mixture was stirred at -78° C. for 30 minutes and methyl iodide (4.62 g, 32.52 mmol) was added. The reaction mixture was slowly warmed to room temperature and stirred at room temperature for two days. To the reaction mixture, 30 ml Et2O and 15 ml 5% aqueous citric acid were added. The organic liquid was separated and washed with 10 ml 5% citric acid, H2O, brine and dried and concentrated. The residue was chromatographed on silica gel using 19:1 hexane/EtOAc to give the title compound of this step (440 mg, 38%) as a light yellow oil.

Provenance & Evidence