229613-83-6

A mixture of (-)-(1R,4S)-2-azabicyclo[2.2.1]hept-5-en-3-one 83 (3.0 g, 27.5 mmol) and 1.25 M HCl in MeOH (59.0 mL, 73.8 mmol) was heated and refluxed for 12 h. The mixture was concentrated under reduced pressure and the residue was stirred with Et2O (42 m