TELE-SUBSTITUTIONS EN SERIE ANTHRACENIQUE-I. COMPORTEMENT DU BROMO-9-METHYL-10 ANTHRACENE VIS-A-VIS DES ANIONS PHENATES ET ALCOOLATES

Article abstract of DOI:10.1016/0040-4020(82)80050-1

Treatment of 9-bromo-10-methyl anthracene 1, in dipolar aprotic solvents, by alkaline phenoxide or alkoxides leads essentially to a mixture of the expected ether, 9-phenoxy (or alkoxy)-10-methyl anthracene 2, normal substitution product (NSP), and of the isomeric ether, 9-phenoxymethyl (or alkoxymethyl)-anthracene 3, tele-substitution product (TSP).It is shown that both ethers must derive from a common unstable intermediate, the 9-bromo-10-methylene-9,10-dihydroanthracene 8, coming from 1 by a prototropic shift and which can undergo both types of substitution.With more hindered phenoxide ions, only the tele-substitution process is observed.