Intramolecular oxidative cyclisation of 1-(4-hydroxyaryl)-2-ketoximes 4-HOArCh 2 C(NOH)R with phenytiodine( III ) bis(trifluoroacetate)

Reaction of 1-(4-hydroxyaryl)-2-ketoximes, 4-HOArCH2C(NOH)R, with phenyliodine(III) bis(trifluoroacetate) in acetonitrile at 0 °C results in smooth intramolecular oxidative cyclisation and formation of 1-oxa-2-azaspiro[4.5]deca-2,6,9-trien-8-ones in good to excellent yield. Attempted application of the procedure to 1-(2-hydroxyphenyl)propan-2-one oxime resulted in formation of the [4 + 2] dimer of the initially formed spiroisoxazoline.