[3+3] Cycloaddition of in Situ Formed Azaoxyallyl Cations with Nitrones: Synthesis of 1,2,4-Oxadiazinan-5-one Derivatives

A [3+3] cycloaddition reaction of the insitu generated azaoxyallyl cations with nitrones under mild reaction conditions is presented. The reaction provides an efficient method to various biologically important 1,2,4-oxadiazinan-5-one derivatives in good to high yields. More importantly, the method can be further expanded to modify some natural aldehydes and drug molecules. The broad substrate scope, mild reaction conditions, and the importance of the corresponding heterocyclic products render this approach attractive and valuable.