The functional group of butyl acetate is related to its chemical properties and ability to react. Butyl acetate has an ester functional group, which is formed by esterification of carboxylic acid and alcohol. The ester group structure is -COO-, in the molecule of butyl acetate, one end is connected to the acetic acid residue and the other end is connected to the butyl group.

The ester group gives butyl acetate specific physical and chemical properties. Physically, it is a liquid with an aromatic odor, which is insoluble in water and soluble in organic solvents. This property is due to the structure and polarity of the ester group. Chemically, the ester group can be hydrolyzed. Under the catalysis of acid or base, butyl acetate is hydrolyzed to acetate and butanol. When catalyzed by base, the reaction is more complete, resulting in acetate and butanol.

Furthermore, ester groups can participate in the alcoholysis reaction, exchange alkoxy groups with other alcohols to form new esters. This property is widely used in the field of organic synthesis, and can prepare ester compounds with different structures and functions.

In summary, the ester functional group of butyl acetate plays a key role in its physical properties, chemical reaction characteristics and applications in organic synthesis, and is the core of understanding and application of butyl acetate-related chemical processes.