The pyrethrins and related compounds. Part XXVII. Esters of pulegenic and related acids

A report by Staudinger and Ruzicka of the insecticidal activity of an ester of pulegenic acid with mixed naturally derived alcohols had not been examined further, and had been misinterpreted in a review. Therefore, two isomeric pulegenic and nine related acids were synthesised, characterised and esterified with modern, more effective, pyrethroidal alcohols. The pulegenic esters were inactive, but low activity was found in esters of acids in which the 5-membered ring was additional to, rather than a replacement for, the cyclopropane ring.