Abstract The condensation of 1H-indol-3-ethanamine derivatives 1 with 1, 2- cyclohexanedione (2) and subsequent transformation of the resulting 2-[[2-(1H-indol-3-yl) ethyl] imino] cyclohexanones (3) into 2′, 3′, 4′, 9′-tetrahydrospiro [cyclohexane-1, 1′-