Remote oxidation of carboxylic acids by peroxodisulphuryl difluoride in fluorosulphuric acid: a general synthesis of lactones
Abstract
Peroxodisulphuryl difluoride, (FSO3)2, generated by constant-current electrolysis of fluorosulphuric acid–potassium fluorosulphate (1.0M), reacts rapidly and smoothly with a series of carboxylic acids (C3–C10) in fluorosulphuric acid at 273 K. Oxidation occurs at a site remote from the carboxy-group and, after work-up, lactones can be isolated in high yields.