The　anodic　oxidation　of　caffeic　acid　in　the　presence　of　sodium　benzenesulfinate　in　aqueous　solution　was　studied　by　cyclic　voltammetry　and　controlled　potential　coulometry.　The　results　showed　that　similar　to　other　simple　catechol　derivatives　where　the　substituents　attached　directly　to　the　benzene　ring,　caffeic　acid　was　oxidized　to　the　corresponding　o-benzoquinone　which　underwent　further　Michael-addition　with　sodium　benzenesulfinate　or　sodium　p-methyl　benzenesulfinate　to　produce　6-arylsulfonyl　caffeic　acid　derivative　7a　or　7b.　(c)　2007　Published　by　Elsevier　B.V.