Abstract The quaternary 3-cyano-quinolinium salt (1b) reacts in aqueous buffer solution (pH 7.5-12) to oxy-di(1.4-dihydroquinoline) (7), which gives on addition of alcohols or oximes in high yields the alcoxy-dihydroquinolines (8a-c) or dihydroquinolyl-oximethers (8d-f).