Abstract In search for nonsteroidal inhibitors of 5α-reductase for the treatment of benign prostatic hyperplasia (BPH) and possibly prostate cancer, substrate mimicks were synthesized comprising of a 1-methyl-2-pyridone (2, 4–16) or 1-methyl-2-piperidone (1, 3, 17–22) moiety (mimicking steroidal ring A) and a diisopropyl (1, 2,(E)-5-(E)-7,(Z)-5-(Z)-7, 11– 13, 17–19) or a tert-butyl (3, 4,(E)-8-(E)-10,(Z)-8-(Z)-10, 14–16, 20–22) benzamide ( ...