Electrosynthesis of 1,2-Dithiolane 1-Oxides from Substituted 1,3-Dithianes

Controlled potential oxidation of a variety of 5-substituted 2-tert-butyl-1,3-dithianes in wet acetonitrile, using an undivided electrochemical cell, provide 4-substituted 1,2-dithiolane 1-oxides selectively and in good yields. Adsorption to the electrode surface of the platinum anode, rendering it passive in the electrolysis of these sulfur-containing compounds is a solvable problem. Although acid-sensitive O-trimethylsilyl ethers are cleaved under the reaction conditions, O-tert-butyldimethylsilyl ethers only suffer cleavage to a modest extent, and an ethylene ketal moiety suffers little, if any, cleavage.