Highly substituted chalcones 1 do not react with two molecules of hydr
oxylamine affording dioximes 2 or hydroxyamino-oximes 3 as expected ac
cording to von Auwers' procedure(1)): only one molecule of hydroxylami
ne is consumed leading to trans-configurated 2-benzoyl-3-phenyl-1H-azi
ridines 4.