novel three-component reaction of alkadienol, CO2, and aryl or vinylic halide gives a vinyl group-substituted cyclic carbonate in one pot in the presence of a catalytic amount of a palladium complex. 2,3-Alkadienol affords five-membered ring carbonate in good yield, while 3,4-alkadienol effects the six-membered one successfully. 2,4-Alkadienol also takes part in this reaction to provide five-membered