Quinone methides (QM) have long been known to play key roles in the mechanism of action of many antitumor agents and natural products such as mitomycin C, adriamycin, and etoposide.(1) The potential toxicity of such intermediates is perhaps most well-known for the over-the-counter analgesic acetaminophen, which is metabolized in the liver to give an N-acyl-p-imino-quinone species that can covalently bind with proteins and nucleic ...