“…Ketene Nary1 imines have been shown to react with electron-rich dienophiles such as ethoxyacetylene, ketene acetal, vinyl ethers and amino acetylenes to form quinoline derivatives46*51. The reaction between diphenylketene N-phenylimine(38) and N-diethylarninophenylacetylene(39) demonstrates this type of cycloaddition (equation 28).…”