A biomimetic reaction between β, β′-diamenoketones (eg kynuramine, kynurenine or o, o′-diaminobenzophenone) and a variety cyclohexanediones and quinones leading to pyrido [2, 3, 4-kl) acridines is described. The synthesis of several di-and tetrahydro-pyrido [2, 3, 4-kl) acridine derivatives (7, 10. 12 and 15) as well as benzoderivatives of the marine alkaloids eilatin (1) and ascididemin (2), compounds 28 and 30, has been accomplished. ...