Quinoline ring formation by cycloaddition of N-arylketenimines with enol ethers under high pressure

The reaction of N-aryl substituted ketenimines with enol ethers under 800 M Pa gave quinoline derivatives, which formed by cyclization between the C=C- N=C aza-diene moieties of N-aryl substituted ketenimines and the C=C double bond moieties of enol ethers. When cyclic enol ethers such as 2,3-dihydrof urans or 3,4-dihydro-2H-pyrans were used as dienophiles, quinoline derivati ves that had substituents with hydroxyalkyl or oxoalkyl side chains on the C-3 positions were synthesized in one step reaction.