The Beckmann Rearrangement of 1,2-Cyclohexane-dione Dioxime in Liquid Sulfur Dioxide

Three different reagents, thionyl chloride, bromine and sulfur trioxide in liquid sulfur dioxide were reacted on 1,2-cyclohexanedione dioxime to yield cyclohexano[c]-1,2,5-oxadiazole, 1-aza-7-oximinocyclohepta-2-one and δ-cyanovaleric acid respectively. Only the bromine in liquid sulfur dioxdie effected the Beckmann rearrangement. Thionyl chloride caused a dehydrative condensation, as has been reported previously. Sulfur trioxide yielded a product resulting from a deoximative cleavage. The reasons for the different processes and the different products have been discussed.