Diselenide- and Disulfide-Mediated Synthesis of Isocoumarins

Cyclizations of stilbenecarboxylic acids to the corresponding isocoumarin derivatives using diselenide or disulfide reagents have been developed. By employing bis(triflouroacetoxy)iodobenzene as oxidant for the 6-endo-trig cyclizations a variety of dihydroisocoumarins have been prepared in good yields. This method is capable of forming isocoumarins and dihydroisocoumarin derivatives by a cyclization-elimination route.