Reactivity in the formation of lactones from aromatic carboxylic acids with organohypervalent iodine compounds in the Suarez system

The reactivity of various iodanes, such as (diacetoxyiodo)arenes, the Dess- Martin reagent, and (arylsulfonyloxy)benziodoxolones, with (o-alkyl)- and ( o-phenyl)arenecarboxylic acids in the presence of iodine (Suarez system)was studied to give the corresponding lactones via oxygen-centered radicals. ( Diacetoxyiodo)arenes gave the lactones in good yields, while 1-(arylsulfony loxy)benziodoxolones gave lactones together with the iodinated lactones. Th e Dess-Martin reagent also showed the same reactivity as (diacetoxyiodo)are nes to give the lactones. Among them, (diacetoxyiodo)toluene showed the bes t reactivity for the conversion of these carboxylic acids to the correspond ing lactones.