Synthesis of dihydrosilanaphthoindolizines and dihydrosilaazaaceanthrelenes

New heterocyclic systems, dihydrosilanaphthoindolizines and dihydrosilaazaaceanthrelenes, have been synthesized starting from 9,10-dihydro-9-sila-3-azaanthracenes. Substituted 6,11-dihydro-6-silanaphtho[2,3-g]indolizines were obtained as a result of 1,3-dipolar cycloaddition reaction of dimethylacetylenedicarboxylate with the quaternary salts of dihydrosilaazaanthracenes having a N-phenacyl group. In a similar manner, substituted 3H,6H-6-sila-3-azaaceanthrelenes, a new pseudoazulene system, have been synthesized from N-benzyl (methyl) quaternary salts. Dihydrosilanaphthoindolizine, having a linear linkage of the dihydrosilanaphtholene and the indolizine cycles has been synthesized from the corresponding dihydrosilaazaanthracene quaternary salt using the Tschitschibabin method. © 1982.