Abstract
Thermal reaction of 2, 2-dimethyl-2H, 4H-1, 3-dioxin-4-ones (1) with amines was studied. Acylketenes 2, generated by heating of 1, reacted with anilines and benzylamine to give the corresponding β-ketocarboxamides (3, 4, and 5) in good yields. The reaction of 1 with ammonia gave 3-amino-2-alkenamides (7), which were hydrolyzed to β-ketocarboxamides (6). The former products 7 were readily transformed to the 6-substituted 2-methyl-3H-pyrimidin-4-ones (9) via the 3-acetamido-2-alkenamides (8). Acylation of O-benzylhydroxylamine with 1 gave the β-ketohydroxamic acids 10. Debenzylation of 10 followed by cyclization gave rise to 5-alkyl-3-hydroxyisoxazoles (12). The reaction of 1 with amides gave the corresponding N-acylated amides (13).
