Electrochemical fluorination of aliphatic aldehydes and cyclic ketones using Et3N-5HF electrolyte

The first electrochemical oxidative fluorination of aliphatic aldehydes (1) and cyclic ketones (3) has' been successfully carried out using Ease-HE as the supporting electrolyte and fluorine source. The selective displacement of formyl hydrogen by fluorine in aliphatic aldehydes electrochemically took place to give acyl fluorides (2) in good yields in the presence of the Et3N-5HF electrolyte. On the other hand, the selective alpha-bond cleavage between the carbonyl carbon and substituted alpha-carbon in cyclic ketones occurred in the presence of the Et3N-5HF electrolyte to give fluoroacyl fluorides (4), which were readily converted in good yields to the corresponding fluorocarboxylic esters (5) by the subsequent alcoholysis. (C) 1997 Elsevier Science Ltd.