Concept:Interchanging ester groups means swapping the alkyl group attached to the carbonyl carbon with the alkyl group attached to the oxygen atom.Explanation:Ethyl ethanoate is CH3COOCH2CH3.The alkyl group on the carbonyl side is methyl, −CH3.The alkyl group on the oxygen side is ethyl, −CH2CH3.After interchanging them, the carbonyl side becomes ethyl, −CH2CH3.The oxygen side becomes methyl, −CH3.The new ester is CH3CH2COOCH3.This compound is methyl propanoate.
