ELECTRO-ORGANIC REACTION: PART 28. PREPARATIVE APPLICATIONS OF THE OXALATE CATHODIC CLEAVAGE REACTION INCLUDING ONE-POT CONVERSIONS OF ALDEHYDES AND KETONES

Article abstract of DOI:10.1016/S0040-4020(01)86879-4

Alcohols and vicinal diols, when co-electrolysed with oxalate esters, undergo transesterification catalysed by cathodically generated base.Under mild conditions at modest cathodic potentials the esters formed in situ give good yields of the corresponding alkanes and alkenes.Furthermore, because diols (pinacols) and alcohols may be efficiently prepared electrochemically from aldehydes and ketones, a one-pot conversion of the carbonyl compounds into alkanes and alkenes has been devised.The method involves prior electrolysis to alcohol or pinacol, addition of an oxalate ester, and further electrolysis for reductive de-oxygenation.Good results are obtained for aromatic ketones and aldehydes.Several oxalate esters have been used in such reactions; diethyloxalate is the most convenient.Esters of squaric acid and of oxamic acid undergo cathodic de-oxygenation but are not convenient in preparative use.