Draw a complete arrow pushing mechanism for the Fischer esterification reaction being performed in this lab. Use highlights (with pen, marker, crayon, highlighter, etc) in your mechanism to illustrate whether the oxygen bonded to the butyl group in the product originates from the carboxilix acid or from the alcohol starting material
THEORY Esters can be made by a variety of reactions. The n-butyl acetate synthesis performed in this lab illustrates the most fundamental method of preparing esters, the Fischer esterification, corresponding to the general equation: H2SO4 + H2O When a carboxylic acid and an alcohol are reacted together in this manner, a strong mineral acid (for example, H,SO) is usually added to catalyze the reaction. R' and R can be any organic group (alkyl, alkenyl, alkynyl, aryl) and they do not have to be the same. n-Butyl acetate is added to a variety of commercial products to create fruit flavours, especially apple, pear, and banana. This ester can also be used as a solvent for laquers, enamels, plastics, leather finishing, rubber and camphor. The "Competition Experiment" section of this lab provides an example of another method of making esters - the reaction of alcohols with carboxylic acid chlorides. UNDERSTANDING THE EXPERIMENT During the two week period since your last lab, the esterification reaction has been proceeding and hopefully will have gone to completion. To separate the desired product from unreacted starting materials and unwanted side products, a distillation is performed. The distilled product will be contaminated with trace amounts of acid and, thus, a neutralization step and drying with MgSO, to remove traces of water are required to obtain reasonably pure product. In the competition experiment, two different alcohols will compete for pivaloyl chloride in the esterification reaction. Which alcohol will win? TLC analysis of the reaction will reveal the answer.
