Several tropolone derivatives (4-7) were designed as novel retinoids on the assumption that the tropolone ring may mimic the benzoic acid moiety in retinoid structures, such as Am80 (2). Among the synthesized compounds, 5-[2-(5, 6, 7, 8-tetrahydro-5, 5, 8, 8-tetramethyl-2- naphthyl) ethynyl] tropolone (7a) showed moderate potency as a differentiation-inducer of HL-60 cells. The activities of the tropolones were greatly enhanced in the presence of ...
