Interesting behavior of α,β-unsaturated oximes in intramolecular [4+2] cycloaddition reactions

Intramolecular [4 + 2] cycloaddition using alpha,beta-unsaturated oximes was explored. The reactions proceeded under unusually facile conditions to furnish the nitrones, The latter were subsequently reacted with DMAD to afford [3 + 2] cycloaddition products.