... RSC Adv., 2014, 4, 8720-8722. ... 8, —, 5% DMSO/Diglyme, Nr c. 9, (NH 4 ) 2 S 2 O 8 (1.0), 5% DMSO/Diglyme, 26. ... image file: c3ra47660j-u2.tif. Various substituted α-oxocarboxylic acids were then tested for this oxidative cleavage/coupling reaction under the optimized conditions. ...