The last ester has a vinyl radical attached to the carbon in the functional group. This forms a three-carbon chain with one double bond in the chain. The name for a three-carbon radical with one double bond is "acryl." The ending for the ester is "ate": so the esta is called acrylate. Any radical can be attached to the oxygen atom in the functional groun If methyl is attached, the ester compound is called methyl acrylate. Figures 5.65 through 5.67 show the structures and molecular formulas for methyl formate, vinyl acetate, and methyl acrylate. There can be other radicals attached to the oxygen atom, which change the name of the compound.