Exam 3B 1. Assign the configurations of the chirality centers as defined be the arrows.

F
H
CH3

_________ OH
H3CH2C

____________

_________ HO
H3C

Cl

__________

CH3 OH H
H

C l

________

H3 C

H

H3 CH C
2 H2 C

CHO

__________ H

2. Which alkyl halide would react FASTEST by SN2 Reaction. Circle the correct Br answer. Br

Br
Ph

Br

Ph

Br

3. State whether the structure in each pair are enantiomers (E), diastereomers (D), or the same structure (Same). Designations may be used more than once or not at all. a. Cl
H
H
HO
OH
Br

I
H
OH

and

__________

I

Br
Cl

H

b.

OH

F

and

__________

F

c. and d.

Br
Br

F
H

Br
CH3

H

__________

Br

and

__________

H
F

H

H

F

Exam 3B

Br

Br

and

________________

________________

OHC

H

and

H

CH3

OH

NH2

H3C

H3C

f.

NH2

H

CH3

OH

H

CHO

e.

4. Complete the following substitution reactions by either writing the major organic product(s) formed, the missing starting material, or the missing reagent(s) as indicated by the box. Be sure to show stereochemistry (wedge-­‐ dash) structures to indicate the configuration at chirality centers. If a pair of enantiomers form, be sure to show both appropriately. a.

Na O
DMSO

b.

Br

I

Na O
DMSO

c.

CN

NaCN
DMF

d.

HBr
Heat

O
Br

H

H

Exam 3B 5. Optically pure (R)-isomer of bupropion (Wellbutrin) is used to assist in smoking cessation, for treating smoking and nicotine addiction, and for treating pain, including, but not limited to, chronic pain and neuropathetic pain, while avoiding adverse affects associated with racemic bupropion. It is also used as an atypical antidepressant. Circle the R enantiomer of bupropion.
O

O

HN

Cl

HN

Cl

6. Show the mechanisms for the following two reactions. Make sure you show all electron and correct pushing arrows. Circle the major product! OH a.

H2SO4
H2O

Heat

O
b.

Br
O

HOCH
O
3

+
+