Introduction to Experimental Organic Chemistry
Reaction of Sodium Borohydride with Different Carbonyl Compounds
: You need to summarize your experimental plan in your lab
notebook. Be sure to include a table of all reagents and compounds that will be used in
Be sure to record any observations during the laboratory.
You must record exactly how much of the starting materials you started with and the
weight of the isolated product.
Results and Conclusions
: Calculate a % yield for the reaction, obtain an IR spectrum of
the product and determine the melting point (if solid) of the product.
At your discretion,
measure the optical rotation of the product.
You will attempt to deduce what your
starting carbonyl compound was from all of your observations.
Technique 1, Crystallization, pp 23-38, Technique 2, Melting Points,
pp 39-48, Technique 3, Extraction, pp 49-70, Technique 4, Drying Organic Solutions, pp
71-75, Technique 14, Carrying Out Typical Reactions, pp 153-162, Technique 15, IR
Spectroscopy, pp 163-178.
Reduction of carbonyl groups is an important chemical conversion in organic
The reduction of these the carbonyl group produces a hydroxyl group.
Reductions can be accomplished by a wide variety of reagents, including
hydrogen with an active metal catalyst, sodium borohydride (NaBH
), and lithium
aluminum hydride (LiAlH
These reagents have differing selectivities in terms of
which type of carbonyl group they will reduce (i.e. aldehydes, ketones, esters, etc.).
the carbonyl compound is not symmetrical (R
are not identical), then it is also
possible to produce more than one product, depending upon which “face” (a carbonyl
group is trigonal planar!) of the carbonyl group the hydride adds to.
Each student will get one carbonyl compound (as an unknown) to perform the
borohydride reduction with.
Using their data and comparing it to other students’ data in
the lab, each person will identify their starting compound and their reaction product(s).