Divergent Reactivity in the Reaction of β-Oxodithioesters and Hydroxylamine: Access to β-Ketonitriles and lsoxazoles

Starting from beta-oxodithioesters and hydroxylamine, two completely different transformations afford either beta-ketonitriles or isoxazoles with high chemoselectivity depending on the reaction conditions. The reaction of beta-oxodithioesters with hydroxylamine in EtOH at room temperature in daylight gave beta-ketonitriles in high yields. On the other hand, 3-methylthio-isoxazoles were efficiently obtained as the final products by heating the mixture of beta-oxodithioesters and hydroxylamine in HOAc at 90 degrees C.