A NEW RING TRANSFORMATION : SYNTHESIS OF 5,5-DIMETHYL-3-OXO-1-PYRROLINE 1-OXIDES FROM 6,6-DIMETHYL-4-OXO-5,6-DIHYDRO-1,2,4H-OXAZINES

Article abstract of DOI:10.1016/S0040-4039(01)90519-2

The nitrosation of some γ,δ-unsaturated β-diketo compounds affords the 3-substituted 4-oxo-5,6-dihydro-1,2,4H-oxazines.These compounds are converted to the isomeric 3-oxo-1-pyrroline 1-oxides by a facile thermal rearrangement.