Water → tert-Butyl 1-oxa-6-azaspiro(2.5)octane-6-carboxylate

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Reaction Steps

Trimethylsulfoxonium iodide (70 g, 0.32 mol) was gradually added to a suspension of sodium hydride (13.3 g, 0.33 mol) in dimethylsulfoxide (600 ml), and the mixture was stirred at room temperature for 1 hour. To which tert-butyl 4-oxo-piperidine-1-carboxylate (58 g, 0.291 mol) was gradually added, and the mixture was stirred at 55° C. for 1 hour. The reaction mixture was poured into iced water, and extracted with diethyl ether. The organic phase was washed with a saturated saline solution, dried over magnesium sulfate, and then filtered. The resultant filtrate was concentrated under a reduced pressure, and the residue was crystallized from n-hexane to afford tert-butyl 1-oxa-6-azaspiro[2,5]octane-6-carboxylate (61.7 g, yield 96%) as a white powder.

Provenance & Evidence