Rearrangements of 5‐acetyl‐3‐benzoylamino‐6‐(2‐dimethylamino‐1‐ethenyl)‐2 H ‐pyran‐2‐one and 3‐benzoylamino‐6‐(2‐dimethylamino‐1‐ethenyl)‐5‐ethoxycarbonyl‐2 H ‐pyran‐2‐one into 1‐aminopyridine, pyrano[2,3‐ b ]pyridine and isoxazole derivatives

Rearrangements of 5‐acetyl‐3‐benzoylamino‐6‐(2‐dimethylamino‐1‐ethenyl)‐2 H ‐pyran‐2‐one ( 1 ) and 3‐benzoylamino‐6‐(2‐dimethylamino‐1‐ethenyl)‐5‐ethoxycarbonyl‐2 H ‐pyran‐2‐one ( 7 ) in the presence of N ‐nucleophiles, such as ammonia, hydrazine, and hydroxylamine, into 1‐aminopyridine, pyrano[2,3‐ b ]‐pyridine, and isoxazole derivatives 5, 11 , and 15 is described. In the reaction of compounds 1 and 7 with C‐nucleophiles, such as 5,5‐dimethyl‐1,3‐cyclohexanedione and barbituric acid, only substitution of the dimethylamino group is taking place to give the compounds 17, 18 , and 20 .