Five novel carbonates, designed as suicide (mechanism-based) inhibitors of acetylcholinesterase, were synthesized and evaluated against the enzyme in vitro and screened for insecticidal activity. The design strategy of inhibition was based on the isosteric relationship of carbonates to the ester of the natural substrate acetylcholine, and on the release of electrophilic quinone methides or alpha-chloroketones at the active site after enzymatic carbonate hydrolysis. Most compounds were inhibitory in vitro, with good specificity for acetylcholinesterase. Some showed modest insecticidal activity. Results of kinetic studies on one analog were consistent with mechanism-based inhibition.