Question

write the complete mechanism for the preparation of banana oil

why do you use sulfuric acid in the reaction

explain why we used simple distillation in order to isolate our product. Describe what is actually happening in the process.

Calculate and discuss your % yield...

explain why reflux is neccesary in this experiment..

Answer 1

Isoamyl acetate (banana oil) is prepared by the acid catalyzed reaction (Fischer esterification) between isoamyl alcohol and glacial acetic acid as shown in the reaction equation below.

Typically, sulfuric acid is used as the catalyst for fast conversion of product from starting alcohol and acid.

The distillation is required because the side product of this reaction is water. From Le Chatelier's principle, there are two ways to adjust reagent concentrations to force isopentyl alcohol to become Isoamyl acetate (product). One way is to remove product (ie. water) as it forms and the other way is to use a large excess of acetic acid.

This experiment attempts to prepare isopentyl acetate from acetic acid and isopentyl alcohol. The reaction is catalyzed by sulfuric acid, but the catalyst affects only the rate of reaction, and not the extent of reaction. The desired product accumulates only if the equilibrium constant is favorable. The equilibrium constant for this reaction is rather small (~4). Therefore, simply mixing equal amounts of the starting materials will convert only about 67% of the starting material into product. So, in order to attain the activation energy for this conversion, reflux condition is required.