Organic Chemistry II
	Professor Carl C. Wamser
Chem 335 - Winter 2008	Exam 1 Answer Key

1a.  (3 points)  Write a clear structure for  4amino-2-benzylbenzoic acid

1b.  (3 points)  Write a clear structure for  3-ethyl-5-nitropyridine

1c.  (6 points)  Write ALL the resonance forms (including Kekule forms) for

1d.  (5 points)  Write ALL the resonance forms (including Kekule forms) for

2.  (15 points)  Give brief definitions of the following terms and include a specific illustration.

a)  s-cis  vs  s-trans  (illustrate with 1,3-butadiene)

b)  1,2-  vs  1,4-addition  (illustrate with 1,3-butadiene)

c)  thermodynamic  vs  kinetic control  (illustrate with 1,3-butadiene AND a potential energy diagram)

d)  activator  vs  deactivator  (illustrate with any appropriate pair of molecules)

e)  aromatic  vs  antiaromatic  (illustrate with any appropriate pair of molecules)

3.  (15 points)  Complete each of the following reactions by writing the structure of the expected product:

a)

b)

c)

d)

e)

4a.  (7 points)  Write an energy level diagram, indicating the number of pi molecular orbitals expected, their relative energies, the number of electrons expected in each orbital, and identifying the HOMO and LUMO for the cation shown below.

4b.  (4 points)  Draw approximate molecular orbital pictures of the HOMO and LUMO of the cation above, indicating orbital symmetries and the presence of any nodal planes.

5.  (15 points)  Isoprene, shown below, can react with one equivalent of HCl in a variety of ways.

a)  Show the two possible 1,2-addition products that are constitutional isomers.

b)  Show all the possible 1,4-addition products including E,Z stereoisomers.

c)  Show the 1,4-addition polymer that could be made from isoprene in both its E and Z forms.
The Z form is natural rubber - indicate which one this is.

6.  (15 points)  Write a complete mechanism for the Friedel-Crafts methylation of chlorobenzene.
Show all steps and all resonance forms for any intermediates involved.
Just show the pathway to  the major product.

7.  (12 points)  Complete the following reaction sequence by filling in the boxes with the missing structures or reagents and conditions.