Organic Chemistry I

 

Professor Carl C. Wamser

Exam 1 Answer Key

1. (15 points) Write complete names for each of the following.

a)

3-chloro-1-(1-methylcyclopentyl)hexane

b)

5-bromo-1,1,1-trichloro-6-ethyl-4-methyloctane

c)

1,3-dichloro-2,3,4-trimethylnonane


2. (15 points) Write accurate structures for the following:

a) anti 1-bromopropane

b) axial bromocyclohexane

c) 1-methylbicyclo[2.2.1]heptane

d) 1-methylspiro[3.4]octane

e) a C5 heterocycle containing one nitrogen


3. (10 points) Answer the following questions about the molecule shown below:

(3) What is the molecular formula?

C10 H13 Cl

(3) Indicate the number of carbons with each hybridization:

sp ______2_____
sp2 _____2______
sp3 _____6______

(4) On the structure, carefully point to ONE example each of a carbon that is

carbons in double or triple bonds are NOT designated 1°, 2°, 3°, or 4°


4. (15 points) Arrange each of the following in order with respect to the property indicated.
Write “MOST” under the compound with the highest value and “LEAST” under the compound with the lowest value.

a) acidity

LEAST / / MIDDLE / / MOST

b) stability

MIDDLE / / LEAST / / MOST

c) boiling point

MOST / / MIDDLE / / LEAST

d) acidity

MOST / / MIDDLE / / LEAST

e) heat of combustion

MIDDLE / / LEAST / / MOST


5. (15 points) Complete the following acid-base reactions and predict whether the equilibrium will be favored to the right or to the left.

a)

b)

c)

Of all the structures shown above (on both sides of your equations), identify which is the

d) strongest acid

HF

e) strongest base

CH3CH2O-


6. (15 points) Give the IUPAC name for the compound shown in the Newman projection below.

2,3-dichlorobutane

Is this its most stable conformation? YES

Write the other two staggered conformations for this compound and compare the energies of all three structures.


7. (15 points) Complete the structure on the right so it represents the other chair conformation of the structure on the left.
Locate all substituents accurately. Circle all axial substituents on both structures.

Can you predict which structure is more stable? Explain.

The structure on the right has more equatorial and fewer axial substituents,
so it is likely to be the more stable form.