Synthesis of isocoumarins and α-pyrones via iodocyclization

A variety of 3-substituted 4-iodoisocoumarins and 6-substituted 5-iodo-2(2H)-pyranones are readily prepared in excellent yields under mild reaction conditions by the reaction of o-(1-alkynyl)benzoates and (Z)-2-alken-4-ynoates with ICl.