Abstract
The reductive cleavage of pyridinium group from N-(α-acyl-2-quinolylmethyl)-pyridinium perchlorate (I) was found to be effected by treatment of I with zinc powder in the presence of potassium acetate in acetic acid under relatively mild conditions to give quinaldyl ketone (II). The tautomeric structures (II-A, II-B and II-C) of aryl quinaldyl ketones (IIb-IIk) were examined by UV, NMR and IR spectroscopies, and it was made clear that II existed chiefly as the enaminic form (II-C) rather than the chelated enolic form (II-B), differently from the case of aryl 2-picolyl ketones (IV).
