Carbonylation products such as alkanoic anhydrides, e.g., acetic anhydrides, are produced by carbonylation of esters and ethers in the presence of a rhodium or iridium catalyst and {HEAD ~ an iodine moiety} in {TAIL ~ a reaction zone} wherein the reaction mixture is in a continuous boiling state 
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Carbonylation products such as alkanoic anhydrides , e.g. , acetic anhydrides , are produced by carbonylation of esters and ethers in the presence of a rhodium or iridium catalyst and { HEAD ~ an iodine moiety } in { TAIL ~ a reaction zone } wherein the reaction mixture is in a continuous boiling state
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