Synthesis of an M?+?7 stable isotope of ?-cyhalothrin

gamma?-Cyhalothrin is a single isomer, synthetic pyrethroid insecticide. This material was originally developed and marketed by Pytech Chemicals, a joint venture between Dow AgroSciences and Cheminova A/S. Cheminova A/S now wholly owns Pytech Chemical. As a part of registration studies, there was a need for a stable isotope of gamma-cyhalothrin to serve as an internal standard. This paper will discuss the 11-step synthesis that was used to prepare an M+7 stable isotope of gamma-cyhalothrin by utilizing triethyl phosphonoacetate-d2 and acetone-d6 to incorporate deuterium into the molecule. In the end, the diastereomers were separated by preparative reverse-phase HPLC to give gamma-cyhalothrin-d7 in an overall yield of 6%. Copyright (c) 2012 John Wiley & Sons, Ltd.