Two synthetic routes to a compound having the structure analogous to the A-ring of tetracycline, 2-phenylcarbamoyl-5, 5-dimethyl-6-(1-piperidyl)-1, 3-cyclohexanedione, were established. The desired compound was obtained by amination of 2-phenylcarbamoyl-5, 5-dimethyl-6-bromo-1, 3-cyclohexanedione with piperidine. The antibacterial properties of the final product are reported.