Question

Two esters with the empirical formula C3H6O2 may be prepared. Write structural formulas for these esters and name them. How would you prepare the two esters?

Answer 1

The given molecular formula C₃H₆O₂ for an ester can be attributed by keeping the carboxyl group COO constant and varying the carbon skeleton attached to the carboxyl carbon and the oxygen. Thus, we can have esters with structural formulas CH₃COOCH₃ and HCOOC₂H₅ named methyl acetate and ethyl formate respectively.

Esterification reactions typically involve the reaction between an acid and an alcohol in the presence of an Arrehenius acid like sulphuric acid as a catalyst for protonation of the hydroxyl group, initiating cleavage and then linkage of the acid and alcohol to give an ester. Thus, Methyl acetate can be prepared by the reaction between acetic acid and methanol with catalytic amounts of concentrated sulphuric acid and ethyl formate can be prepared by reaction between formic acid and ethanol again with sulphuric acid as the catalyst.