The pyrethrins and related compounds. XVII. Preparation of the insecticide bioresmethrin (5‐benzyl‐3‐furylmethyl (+)‐trans‐chrysanthemate) and related compounds labelled with deuterium or tritium on the furan ring

Abstract 2‐2H‐5‐Benzyl‐3‐furylmethyl esters exclusively are obtained from an exchange reaction of the parent esters with deuterium oxide and a trace of acid (n.m.r. and mass spectrometric control). Similarly, with tritiated water, 6 insecticidal esters of 5‐benzyl‐3‐furylmethyl alcohol give the corresponding [2‐3H]esters, each with specific activity of approx. 500 mCi/mmol.