A study of the dehydrochlorination of DDT in selected solvent media

Abstract

The rate constant for the E2 elimination of DDT with sodium methoxide in methanol was found to fall continuously as water was added to the Solvent, in marked contrast to the behaviour of other elimination reactions under these conditions. This anamoly could arise if the transition state for the E2 reaction of DDT is of the "classical" type, with a highly dispersed charge and the other substrates had a "Winstein-Parker" type of transition state. If this were the case, the Hughes - Ingold effect of solvent change would be much more noticeable with DDT. The rates of E2 elimination of DDT and dibromoethylene with sodium methoxide in dioxane - methanol mixtures have been measured in an attempt to test this theory but no other indication of a particularly large Hughes - Ingold effect in DDT has been found.