Formation and synthetic use of oxygen-centred radicals with (diacetoxyiodo)arenes

o-Alkyl- or o-aryl-benzenecarboxylic acids and alcohols containing an aromatic ring are treated with a (diacetoxyiodo)arene–iodine system to give the corresponding cyclized products such as phthalide, benzocoumarin and chromane derivatives in moderate to good yields via the corresponding oxygen-centred radicals. For the carboxylic acids, [bis(trifluoroacetoxy)iodo]benzene functions effectively, while (diacetoxyiodo)benzene is effective for the alcohols. Chromane and its derivatives are obtained as iodinated compounds by hypoiodite species derived from (diacetoxyiodo)benzene and iodine.