Chemistry Department

 

University of Alberta

           

CHEM 261

 

Exam I

 

February 12, 2008

 

1. From the perspective of viewing along the bond between carbon 2 and carbon 3, draw the Newman projection of the most stable conformation of 2,3-dimethylbutane.

 

 

2. Give the structural formula of each of the following compounds:

 

a.    cis-4-isopropyl-2-octen-1-ol

 

 

b.    oxacyclobutane

 

 

3. Name the following compounds:

 

1.  

 

 

2-methoxybicyclo[3.3.1]nonane

 

2.  

 

                       

 

                                trans-4-butyl-7-methyl-5-octen-2-yne

 

4. The pK_a of H₂ is 35 and that of (CH₃)₃COH is 18.

 

a.    Draw the products of the following reaction.

 

                       

 

                               

 

b.    Determine the direction of the equilibrium and explain your answer.

 

It lies to the right as H₂ is the weaker acid.

 

5. In each of the following pairs of acids, circle the stronger base:

 

           

1.  

 

 

2.  

 

                               

 

3.  

 

           

6. The IR spectrum of a compound of molecular formula C₁₁H₈O is given below. Identify the functional group.

 

 

 

            aldehyde

 

 

7. Calculate the degree of unsaturation indicated by the molecular formula C₁₁H₈O.

 

(2 x 11 – 8 + 2)/2 = 8

 

 

8. Juvenile hormone is produced by the male wild silk moth Hyalophora cecropia L., and its presence prevents the maturation of insect larvae:

 

           

           

a.      Name the oxygen-containing functional groups in Juvenile hormone.

 

Ether and ester

 

b.      Estimate the bond angle labeled A.

 

109.5°

 

c.      What is the classification of the carbon labeled B? (Primary, etc.)

 

tertiary

 

d.      What is the hybridization of the oxygen labeled C?

 

sp³

 

9. Draw the functional group of a secondary amine.

 

 

 

10.  Draw the resonance structures of the following cation:

 

 

 

 

 

11. Compound A has molecular formula C₃H₆O.  Its IR spectrum shows no peaks in the 3500 - 3300 cm^-1 region and none in the 1650 - 1750 cm^-1 region.  Propose a structure for compound A.