Reaction of pyrylium salts with nucleophiles—VII

摘要: Abstract The reaction of 2,4,6-triphenylpyrylium (II) with hydroxylamine affords the monoxime (IVB, Y = O) pseudobase. It isomerizes readily into 3,5-diphenyl-5-phenacyl-2-isoxazoline (VB, O). Mineral acids split IVB or VB (Y acetophenone and 1,3-diphenylisoxazole (VII, Similarly, products II ith phenylhydrazine (“α-” “β-pyranolhydrazides”) afford on treatment hot mineral 1,3,5-triphenylpyrazole acetophenone. structures previously proposed for these “pyranolhydrazides” must be changed NPh). structure product hydrazine is different will discussed in a later report.