Regiospecific -lactam ring-opening/recyclization reactions of N-aryl-3-spirocyclic--lactams catalyzed by a LewisBrnsted acids combined superacid catalyst system: a new entry to 3-spirocyclicquinolin-4(1H)-onesElectronic supplementary information (ESI) available: experimental procedures, analytical data, and spectra copies of all compounds. CCDC 816903. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c1cc15881c

The regiospecific -lactam ring-opening/recyclization reaction of N -aryl-3-spirocyclic- -lactams, made by the one-pot cyclization reaction of acetoacetanilides, has been achieved for the first time using a LewisBrnsted acids combined superacid catalyst system, thus providing an efficient entry to 3-spirocyclicquinolin-4(1 H )-ones. A mechanism involving superacid-catalysis was proposed. The first regiospecific -lactam ring-opening/recyclization reaction of N -aryl-3-spirocyclic- -lactams has been achieved using a LewisBrnsted acids combined superacid catalyst system.