1-Benzyl-4-piperidone → 6-Benzyl-1-oxa-6-azaspiro(2,5)octane

Participants

Reaction Steps

Sodium hydride (55% suspension in mineral oil, 1.57 g, 35 mmol) was washed with heptane, dried in the stream of nitrogen and suspended in dry DMSO (10 ml). A solution of trimethylsulfoxonium iodide (4.8 g, 22 mmol) in DMSO (45 ml) was added dropwise under nitrogen. After stirring for 20 min a solution of 1-benzylpiperidin-4-one (3.78 g, 20 mmol) was added dropwise. The mixture was stirred overnight at room temperature, then poured over ice (200 g), and extracted with dichloromethane (2×200 ml). The combined extracts were washed with water (3×100 ml) and dried over Na2SO4. The solvent was removed i. vacuo. The residue was dissolved in diethyl ether, and the insoluble material was removed by filtration. Evaporation of solven afforded pale-yellow oil (2.95 g, 73%).

Provenance & Evidence