The oxidation of some enamines with metal oxidants

4-(1-cyclohexen-1-yl)-morpholine, 1-morpholino-styrene and 1-morpholino-2-methyl- styrene were treated with lead tetraacetate. The products obtained were N-acetyl-morpholine, the 2-acetoxy-ketone and in the case of the first substrate its enamine. The 2-morpholino-ketone was also formed in the reactions with 4-(1-cyclohexen-1-yl)-morpholine and 1-morpholino-2-methylstyrene. 4- (1-cyclohexen-1-yl)-morpholine reacted with thallium triacetate and mercuric diacetate, giving very similar results. A mechanistic scheme is discussed, where an intermediate product derived from the addition of two acetoxy groups to the enamine double bond is cleaved via an α-elimination path.