Electroreduction of Organic Compounds, 37 [1]. Electroreduction of 1,4-Dichlorobicyclo[2.2.2]octane-2-carboxamides

Abstract

Several 1,4-dichlorobicyclo[2.2.2]octanecarboxamides were prepared, which were expected to be suitable precursors for the electrochemical synthesis of [2.2.2]propellanes. Their potentiostatic electroreduction at extremely negative potentials in THF, however, did not lead to the expected [2.2.2]propellanes. Instead, protio-dechlorination to form the corresponding bicyclo[2.2.2]octanecarboxamides occurred, even under rigorous exclusion of moisture and oxygen. Ring-opened olefins were produced as by-products. Polytetrahydrofuran was formed when the supporting electrolyte tetrabutylammonium hexafluorophosphate was electrolyzed at −3.5 V in the absence of an organic chloro compound as depolarizer. The experimental results are interpreted in terms of semi-empirical MO calculations.