Practical Reactions / FGI

Curtius Rearrangement

A mixture containing 4-(methoxycarbonyl)bicyclo[2.2.2]octane-1-carboxylic acid (100 mg, 0.471mmol), diphenyl phosphoryl azide (130 mg, 0.471 mmol) and Et3N (0.07 mL, 0.500 mmol) in toluene (4 mL) was stirred at room temperature for 2 h. It was then stirred under reflux for 2 h. At this point, benzyl alcohol (1 mL, 1.0 mmol) was added. The resulting reaction mixture was stirred under reflux for an additional 16 h. The reaction mixture was cooled to room temperature and washed successively with a 10% aqueous citric acid, saturated aqueous solution of NaHCO3 and brine. The organic layer was dried (Na2SO4) and concentrated under reduced pressure to afford methyl 4-(benzyloxycarbonylamino)-bicyclo[2.2.2]octane-1-carboxylate as a thick, light brown oil (162 mg, essentially quantitative yield).

WO2008100423

Diphenyl Phosphoryl Azide (DPPA) / 26386-88-9

クルチウス転位 Curtius Rearrangement
Curtius Rearrangement