Small ring chemistry in crop protection

An overview is given of the significance of three- and four-membered rings in crop protection chemistry. The main herbicidally, fungicidally, and insecticidally active small ring derivatives are presented, together with their synthesis routes, modes of action and biological efficacies. Also the most important small ring containing natural products, which are active against weeds, insects and fungal plant diseases are covered. In addition, the role of three- and four-membered rings as intermediates in the synthesis of agrochemicals not containing such a small ring component is reported. (C) 2019 Elsevier Ltd. All rights reserved.