The reactivity of pyridinium salts 2 towards nucleophiles has been studied. The interaction with enolates derived from esters 1 gave only trace amounts of the expected compounds 3. Irreversible-type additions, however, allowed the preparation of indolyldihydropyridines 8 and 9 with high yields. Reaction of organometallic 10 with salt 2c, followed by acidic cyclization, afforded tetracycle 12.
