Download Final Exam Review Sheet Chemistry 110a/1998

Final Exam Review Sheet
Chemistry 110a
The final exam questions will seek an integrated understanding of the material found in
chapters 1-13. You will be allowed to use the following when working your final exam:
a calculator, molecular models, 13 pieces of unlined white 8.5 x 11 inch paper on which
you may hand-write any information to your liking on both sides of the paper. These
“study aids” will be due at the end of the exam period and the quality of your notes will
factor into your final exam grade. Retain a copy of your notes for your own records.
Please consult your prior exam review sheets in preparation for the final exam.
Chapter 12: Carbonyl Chemistry
1.
The oxidation series (R-OH, RCHO, RCOOH, etc.). Assignment of
oxidation states of carbon in organic compounds.
2.
Lithium aluminum hydride (LAH) reduction of aldehydes, ketones, esters, acids.
Mechanism of reaction. Sodium borohydride reduction of aldehydes and ketones.
Mechanism of reaction. Compare different experimental conditions and
“reducing power” for LAH vs. NaBH4.
3.
Enantioselective reduction of ketones with Alpine-borane. Mechanism of
reaction and origin of enantioselectivity.
4.
Cr(VI) oxidation of alchohols. Mechanism of reaction. Be able to explain why
3° ROH do not react, 2° ROH gives ketones, 1° ROH gives aldehydes (using PCC
as reagent), 1° ROH gives acids with aqueous chromic acid (Jones Oxidation).
What did the isotope effect tell us about the mechanism of the Jones oxidation?
What aspect of the PCC oxidation allows the oxidation to stop at the aldehyde
stage, whereas the Jones takes the compound to the acid? How does a
Breathalyzer work?
5.
Preparation and reaction of organolithiums, organocuprates, and
organomagnesiums. You should be able to use these reagents in synthetic
applications, and be aware of the scope and limitations of these reagents.
6.
You should be able to utilize these reactions in combination with earlier reactions
we have studied for the evaluation and/or design of synthetic proposals that start
with cheap and readily available starting materials.
Chapter 13: Conjugation; the Diels-Alder Reaction
1.
You should be able to rationalize the extra stability offered to the allylic radical,
cation, and anion using a resonance and molecular orbital argument. How does
the allylic radical compare in stability to 3°, 2°, and 1°? How about the allylic
cation, in this regard? The pKa of an allylic hydrogen is 41: how can you use
this value to say that the allylic anion is more stable than the corresponding 1°
alkane?
2.
Allylic bromination with NBS. Mechanism of reaction. Why don't you get any
Br2 addition to the double bond with this reagent?
3.
You should be able to rationalize the added stability of conjugated double bonds,
using a resonance and a MO argument.
4.
1,2 vs. 1,4 addition to conjugated double bonds: kinetic vs.
thermodynamic control of chemical reactions.
5.
The Diels-Alder reaction for constructing six-membered rings. What are the
properties of the diene and dienophile? Be able to explain why the Diels-Alder
reaction is highly stereospecific.
6.
UV-Vis spectroscopy. Origin of the absorption phenomenon and application in
quantitation.