Synthesis and a Novel Fragmentation of 6-Alkoxy-5,6-dihydro-4<i>H</i>-1,2-oxazine 2-Oxide

Abstract

Abstract An electron-deficient nitro olefin, methyl α,p-dinitrocinnamate, reacts with vinyl ethers to give cyclic nitronic esters, which are stable as compared with those produced by reactions of nitro olefins with enamines. Stability of the cyclic nitronate depends on the properties of the substituents at 4- and 6-positions of the ring. The adducts undergo fragmentation by a catalytic amount of base to β,γ-unsaturated α-hydroxyimino esters.