Studies on Pyrimidine Derivatives. XL. : Ring Transformation of 4-Alkoxypyrimidine 1-Oxides by Reaction with Diketene

Abstract

Treatment of 4-alkoxy-6-methylpyrimidine 1-oxides with acetic anhydride followed by reaction with diketene gave 7-acetyl-4-alkoxy-2-methylisoxazolo[4, 5-c]pyridines and 7-acetyl-4-alkoxy-3-methyloxazolo[4, 5-c]pyridines, respectively. The structure elucidation of these compounds on the basis of spectral data and chemical reactions, and the reaction pathway of the ring transformation are described.