ELECTROCHEMICALLY INDUCED OXIDATIVE REARRANGEMENT OF ALKYLIDENEMALONATES

Alkylidenemalonates capable of double bond migration being electrolyze d in methanol or ethanol in the presence of alkali metal halides in an undivided cell equipped with Fe cathode are transformed into 2-alkyl- 3,3-dimethoxyalkane-1,1-dicarboxylates in 70-90% yield via electrochem ically induced oxidative rearrangement. Acidification of the reaction mixture after the electrolysis leads to the formation of 2-alkyl-3-oxo alkane-1,1-dicarboxylates. In the case of isobutylidenemalonate, the e lectrolysis intermediate dimethyl 3-dimethyl-2-methoxycyclopropane-1,1 -dicarboxylate was isolated in 70% yield. (C) 1998 Published by Elsevi er Science Ltd. All rights reserved.