Stuff to Know for Exam 2, 22104

General (220 stuff)  Lewis structures, formal charges, hybridization rules and corresponding geometries, basic requirements for an H-bond, curved arrow notation, recognition of electrophiles, nucleophiles, and leaving groups.  General mechanisms for acid-base, SN2, SN1, E2, E1, addtion of HX to alkenes, and the noble gas rule.

Chapter 14

1.         know what conjugation means

2.         understand the concept of resonance and how it can be estimated from heats of hydrogenation

3.         recognize that conjugated systems behave as extended pi systems not discrete double bond units.

4.         with respect to 3), how resonance can be described in terms of Lewis resonance structures and MO theory.

5.         Be able to draw diene resonance structures.

6.         understand the following terms, bonding MO, nonbonding energy level, antibonding MO, node, sigma bond, pi bond, aufbau order

7.         be able to determine whether or not a MO is bonding

8.         be able to generate qualitatively various MO's for linear polyenes

9.         know the mechanism for the addition of HX to dienes (1,2 and 1,4)

10.       know the difference between kinetic and thermodynamic control

11.       know the definition of a pericyclic rxn

12.       know the mechanism of the Diels-Alder rxn

13.       know the characteristix associated with the diene in a DA rxn

14.       know the characteristix associated with the dienophile in a DA rxn

15.       Be able to draw DA products

16.       Recognize that the DA rxn proceeds with facility because it has 6 mobile electrons and that the transition state is aromatic and thus has a small energy of activation.

Chp 15

1.         know the various ways to represent benzene rings

2.         know common names for benzene derivatives (toluene, naphthalene, phenol, aniline, benzoic acid)

3.         know the IUPAC system for naming benzene derivatives

4.         understand the thermodynamic evidence for aromatic rings being uniquely stable

5.         know the structural characteristics associated with aromaticity and be able to recognize aromatic mollies 

            (including ions and heteroaromatics)

6.         be able to recognize antiaromatic species and how they deal with their antiaromatic nature (cyclooctatetraene and cyclobutadiene for example)

7.            understand the MO differences between aromatic and antiaromatic species

Chap 16

1.         know the generic version of EAS

2.         recognize the key element of each individual EAS rxn , that the electrophilic species must be activated by some acidic catalyst (either Bronsted or Lewis)

3.         know the individual EAS rxns, mechanisms, and products

4.         know the characteristics of Friedel-Crafts alkylation and acylation

5.            recognize how different substituents can affect electron density in an aromatic ring (donating vs. withdrawing, inductive vs. resonance).

6.         know how electron donation and electron withdrawl with affect EAS rxns rate-wise

7.         know which substituents do what in terms of rxn rates and substitution patterns (o,m,p)

8.         know the underlying arguments (words and pictures) for explaining the stuff in 6 and 7.

9.         understand why polyrxn is a problem for alkylation but not the others.

10.       be able to predict the major product(s) for EAS on disubstitued arenas

11.       know how N substituents can be modified (NO2 à NH2, NH2 à NHCOR, NH2 à N2+,  ArN2+ à multiple possibilities)

12.       know how C substituents can be modified (ArCOR à ArCH2R,  Ar-CHR2 à ArCO2H

13.       be able to propose multistep syntheses to construct disubstituted arenes.

Chp 17

1.    know how to discern whether a transformation is an oxidation, a reduction, or neither
2.    know the structures of the Cr (VI) reagents used for alcohol oxidation
3.    know how alcohol oxidations differ by subclass and reagent
4.    know the mechanism for alcohol oxidation (chromate ester to carbonyl)
5.    understand the use of H2CrO4 as a qualitative test for alcohols, also how H2CrO4 is made.

Chp 18.

1.         Ether synthesis (oxymercuration), know mechanism, reagents, strategy for selection of alkene and alcohol, regiochemistry, and rational for regiochemistry.

2.         ether synthesis (epoxidation), know reagents, stereochemistry

3.         ring opening rxns of epoxides.  For the SN2 version know the pH conditions required, the mechanism, and the regiochemistry.  For the charge-directed SN2 rxn know the pH conditions required, the mechanism, and regiochemistry.

Study hard over multiple days for best results.  We'll talk about homework 8(or whatever you want during our Monday nite help session).    If you have any questions call me [321-4186(W)/433-4493(H)], see me, or e-mail me.  I'm more than happy to help you.  Types of problems potentially on exam 1:  definitions, multiple choice (probably from old MCAT exams if I can get a hold of them), short answer, predict the product, provide reagents, and assemble structure from spectra.  As per usual I'll be shooting for medium tough but fair.  Good luck!