Alcohols II continues the study of this class of compounds and includes an extensive
list of alcohol reactions and analysis. A section addressing balancing
organic oxidation-reduction reaction is included. Alcohols are introduced
as lead players in the role of synthesis development.
The reactions addressed in this unit include dehydration, substitution,
alkoxide formation, oxidation, reduction, esterification, tosylation,
and the Pinacol rearrangement. In the section on dehydration, the
use of phosphoryl chloride is introduced and the way in which dehydration
using that reagent differes from dehydration with sulfuric acid
is noted. Just as the mechanism for dehydration with sulfuric acid
was addressed in a prior unit, the mechanism for dehydration using
phosphoryl chloride is detailed, here. Substiution vs. Elimination is constantly reviewed.
Again, the order of oxidation/reduction of organic compounds is
reviewed and stressed as an aid to learning the oxidation products
forming and being formed by alcohols. Comparison of first, second,
and third degree alcohols and their oxidation products are made.
The use of pyridinium chlorochromate as a substitute for the hot
copper wire is introduced as an easy method for oxidizing alcohols
to aldehydes rather than acids. The commonly expected oxidizing
agents such as potassium permanganate, sodium dichromate in both
acid and base, as well as the Jones reagent, etc. are used. Esterification
without mechanism is discussed for both reactions of alcohols with
organic and inorganic acids. Again, patterns of reactions are stressed,
as well as usage in such fields as biology and biochemistry. A similar
reaction, tosylation using tosyl chloride, is presented and compared
as an esterification process. The mechanism for esterification is
presented in detail in a later unit entitled Derivatives of Carboxylic
Acids. At that point, the two different mechanisms are developed,
beginning with Fisher esterification of first, second, and third
The Pinacol rearrangement is an elegant process that brings together
many aspects of reactions regarding alcohols. The mechanism and
stabilizing structures are presented in this section.
All too often, organic students need to be able to balance organic
reactions but become lost when they attempt to determine the oxidation
number of the various atoms involved. Although it is common to write
the unbalanced equation with reagents or catalysts placed over and
under the arrows, such does not lend itself to producing an equation
suitable for sometimes-required calculations. The Chemistry Professor
has developed a section to address a straight-forward method of
balancing these oxidation-reduction reactions of organic chemistry,
and it is presented at the end of this unit.