Methanol → tert-Butyl 2-oxa-9-azaspiro[5.5]undecane-9-carboxylate

Participants

Reaction Steps

Diethyl diazenedicarboxylate (390 μL, 2.46 mmol) was added to a solution of 1,1-dimethylethyl 4-(hydroxymethyl)-4-(3-hydroxypropyl)-1-piperidinecarboxylate (Description 137, 560 mg, 2.05 mmol) and triphenylphosphine (646 mg, 2.46 mmol) in tetrahydrofuran (10 mL) and the mixture was stirred at room temperature for 24 hours. Further triphenylphosphine (646 mg, 2.46 mmol) and diethyl diazenedicarboxylate (390 μL, 2.46 mmol) were added and the mixture was stirred at room temperature for 24 hours. Methanol (5 mL) was added and the solvent was evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with isohexane/EtOAc (75:25), to give the title compound (78 mg, 15%). m/z (ES+) 256 (M+1).

Provenance & Evidence