Push-Pull Triafulvenes from 1,1'-Oxy-di and 1-pyridinium Salts

Article abstract of DOI:10.1055/s-1988-27649

1-pyridinium salt 6 reacts with activated methylene compounds 7 in the presence of pyridine to give triafulvenes 8.The use of 1,1'-oxy-di<2,3-bis(dimethylamino)cyclopropenylium> salt 5 for the same purpose is limited: with the ambident anions of 1,3-diketones, enol ether salts 9 are formed in some cases at the complete expense of triafulvenes 8.Compound 8n, however, can be obtained only from 5.