Mj. Aurell et al., SYNTHESIS OF DIENEDIOIC AND TETRAENEDIOIC ACIDS BY OXIDATIVE COUPLINGOF UNSATURATED CARBOXYLIC-ACID DIENEDIOLATES BY 1,2-DIIODOETHANE, Synthetic communications, 23(20), 1993, pp. 2827-2831
Acyclic and cyclic unsaturated carboxylic acids 1 to 4 are most easily
converted to unsaturated dicarboxylic acids 5 to & by oxidative coupl
ing of their diene- or triene-diolates by 1,2-diiodoethane. This proce
dure improves formerly reported oxidations by iodine or silver salts.