Study of the reaction of bis- and tris-pyrylium and -thiopyrylium cations with methoxide ion. Electronic effects of the heterocyclic rings as substituents

Article abstract of DOI:10.1021/jo050884a

The bis- and tris-pyrylium and thiopyrylium cations 1-4 were prepared in gram scale by heterocyclization of the corresponding bis- and tris-1,5-pentanediones 6 and 8. Their reaction with CD₃ONa in CD ₃OD was studied by ¹H