Download Exam 2 Review A

Chemistry 110A Exam 4 Review Sheet
Review Session: Wednesday, November 2, 7:00 PM, SN 111
Exam 4: Friday, November 4, 7:50 AM, SN Aud
Chapter 8
1. Be able to explain the addition of HX to alkenes and alkynes as a regioselective reaction,
and be able to employ an arrow-pushing mechanism to explain how this reaction
proceeds.
2. Be able to write a definition of Markovnikov’s rule, and employ the Hammond-Leffler
postulate in an explanation of the regioselective addition of HX to an unsymmetrical
alkene.
3. Be able to explain how alkenes can be hydrated with water under acidic conditions,
using an arrow-pushing mechanism to explain how the reaction works.
a. Be able to explain the differences between this reaction and the reverse
process, i.e., the acid-catalyzed dehydration of alcohols to form alkenes.
4. Be able to explain how alkenes can be hydrated in a Markovnikov fashion using
oxymercuration-demercuration, using an arrow-pushing mechanism for first step of this
process.
5. Be able to explain how alkenes can be hydrated in an anti-Markovnikov fashion using
hydroboration-oxidation, using an arrow pushing mechanism for the entirety of the
process. Be able to incorporate structural features into your example so that you can
explain the stereochemistry of addition/oxidation.
6. Be able to explain the regio and stereospecific addition of Br2 and Cl2 to alkenes and
alkynes, using an arrow-pushing mechanism to explain how this reaction works.
7. Be able to explain the regio and stereospecific addition of Br2/H2O and Cl2/H2O to
alkenes and alkynes (the halohydrin reaction), using an arrow-pushing mechanism to
explain how this reaction works.
8. Be able to explain the reactions of carbenes with alkenes, using an arrow-pushing
mechanism [with the exception of 8c] to explain how these reactions work, starting
from:
a. A base-induced alpha-elmination of chloroform.
b. Diazomethane.
c. The Simmons-Smith reagent.
9. Be able to explain how OsO4 or KMnO4 can be used with variable success to syndihydroxylate alkenes, using an arrow-pushing mechanism to explain how the addition
step of these reactions work.
a. Be able to qualitatively explain how OsO4 can be used in a catalytic manner,
i.e., the Upjohn process.
10. Be able to write down the cleavage products of alkenes and alkynes when treated with
hot KMnO4 or O3.
a. Be able to use these reactions in syntheses and to degrade molecules in order
to determine their structure.
11. You should be able to predict the products of these reactions and be able to
incorporate any of these into a synthesis of a small organic compound.
Chapter 9
1. Be able to explain the physical basis of NMR spectroscopy in terms of spins, energy
levels, a magnetic field, and radiowaves.
2. Be able to explain the origin of factors affecting the chemical shift, such as diamagnetic
shielding, electronegativity, and ring current effects.
3. Be able to use the Beer’s Law aspect of NMR spectroscopy to quantify NMR signal
integrals in 1H spectroscopy as arising from integral numbers of hydrogen atoms.
4. Be able to explain the qualitative origin of spin-spin “J” coupling in NMR spectra, the
‘n+1 rule, and how this rule can be used to establish fragment structures.
5. Be able to qualitatively describe how a rapid molecular process (conformational
interchange, proton exchange) leads to averaging in NMR spectra.
6. Be able to assign groups in molecules as enantiotopic, homotopic, diastereotopic, and
heterotopic, and be able to predict how these designations will manifest themselves in
NMR spectra
7. Be able to explain why 13C spectra consist of single peaks for each carbon atom, and
why these spectra are much noisier than 1H spectra.
8. Be able to explain how mass spectrometry works and how it can be used to determine a
molecular weight and molecular formula for small organic molecules.
9. Be able to assign a chemical structure that is consistent with mass spectral, 1H, and 13C
NMR data, or vice-versa.