Optimization of Reactions
The major aims in developing a synthesis are to optimize the yield and purity of each step. These aims do not necessarily go hand in hand, and it may be necessary to accept a lower than optimum yield in order to obtain high purity. At the same time, such issues as cost and safety have to be considered. The hydrolysis of esters is usually carried out under basic conditions with heating, but this can prove a problem if asymmetric centers are present, since heating in base may lead to their epimerization. The choice of solvent can be crucial to the outcome and the yield of a reaction. Primarily, a solvent is required that will dissolve the reactants and reagents, and ensure that reaction will take place. Solubility is not the only issue to consider when choosing a solvent. Sometimes the outcome and yield of a reaction can be affected by reversing the addition of the reactants.