tert-Butyl 4-methoxy-4-(2-diazo-1,3-dioxopent-1-yl)piperidine-1-carboxylate → tert-Butyl 4-oxo-3-(1-oxoprop-1-yl)-1-oxa-8-azaspiro[4.5]decane-8-carboxylate

Participants

Reaction Steps

A solution of rhodium acetate dimer (0.002 g, 0.005 mmol) in dichloromethane (27 mL) was heated to 81° C. A solution of tert-butyl 4-methoxy-4-(2-diazo-1,3-dioxopent-1-yl)piperidine-1-carboxylate (0.092 g, 0.270 mmol) from Step D in dichloromethane (7 mL) was added slowly dropwise over 12 min. The reaction mixture was refluxed for 45 min then poured into IN hydrochloric acid, and extracted three times with dichloromethane. The organic layers were combined, washed with saturated sodium chloride solution, dried over sodium sulfite, filtered, and concentrated. The residue was purified by flash chromatography eluting with 10% ethyl acetate/dichloromethane to afford the title compound (0.034 g).

Provenance & Evidence