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
1. Be able to explain how to assign the oxidation states of carbon in organic compounds,
and be able to rank order a series of functional groups in terms of their oxidation states.
2. Be able to explain how lithium aluminum hydride (LAH) can be used to reduce
aldehydes, ketones, esters, and acids, using an arrow-pushing mechanism to explain
how the reaction works.
3. Be able to explain how sodium borohydride can be used to reduce aldehydes and
ketones, using an arrow-pushing mechanism to explain how the reaction works.
4. Be able to explain the reactivity differences, i.e., chemoselectivity differences, between
LAH and sodium borohydride.
5. Be able to analyze a figure depicting an enantioselective ketone reduction using Alpineborane, accounting for the structural interactions responsible for the high levels of
enantioselectivity.
6. Be able to explain how a Cr(VI) oxidation (Jones oxidation) of an alcohol is thought to
mechanistically proceed:
a. Explain why 3° alcohols do not react.
b. Explain why 2° alcohols are converted to ketones.
i.
Be able to explain how a kinetic isotope effect can be used to determine the
rate-determining step of this oxidation process.
c. Explain why 1° alcohols are converted to carboxylic acids.
d. Explain how 1° alcohols can be converted to aldehydes when PDC is used as the
reagent in anhydrous dichloromethane.
e. Explain how a Cr-based breathalyzer works.
7. Be able to explain the structure and reactivity of organolithiums and organomagnesiums
(Grignard reagents) towards aldehydes, ketones, and esters/lactones, using arrowpushing mechanisms to explain how these reactions work.
8. Be able to explain the structure of organocuprates and how they can be combined with
electrophiles to form carbon-carbon bonds (a mechanistic explanation is not required).
9. Be able to utilize the preparative reactions learned thus far to guide the evaluation and
design of synthetic proposals that begin with cheap and readily available starting
materials.
Chapter 13
1. Be able to rationalize the extra stability offered to the allylic radical, cation, and anion
using a resonance and molecular orbital argument.
2. Be able to explain relative stability of the allylic radical in comparison with 3°, 2°, and 1°
radicals.
3. Be able to explain relative stability of the allylic cation in comparison with 3°, 2°, and 1°
cations.
4. Be able to explain why the pKa of an allylic hydrogen is 41, in comparison with a
corresponding 1° alkane hydrogen.
5. Be able to explain the allylic bromination of organic molecules with N-bromosuccinimide
(NBS), using an arrow-pushing mechanism to explain how the reaction works and avoids
the reaction of Br2 and the alkene.
6. Be able to rationalize the added stability of conjugated double bonds, using a
resonance and a MO argument.
7. Be able to explain the reaction of HBr or X2 to conjugated double bonds under kinetic or
thermodynamic control, using an arrow-pushing mechanism and a potential energy
diagram analysis of any relevant intermediates.
8. Explain how the Diels-Alder reaction can be used to construct six-membered rings, using
an arrow-pushing mechanism and a HOMO-LUMO orbital correlation to explain how the
reaction proceeds, and how secondary orbital interactions may be used to explain how
it does so with endo selectivity.
a. Explain the electronic properties of the diene and the dieneophile.
9. Explain the basis of UV-Vis spectroscopy and the origin of the absorption phenomenon.
Explain the basis of color in highly delocalized pi systems found in organic molecules
such as -carotene.
10. Hold all organic knowledge close to your heart and water twice a day with your tears of
joy.