Chemistry Department

 

University of Alberta

           

CHEM 263 B1

 

Exam I

 

Thursday, February 10, 2011

 

                                                                                                               

1. The IR and ¹H NMR spectra of a compound of molecular formula C₁₁H₁₆O are given below. 

 

SDBSWeb : http://riodb01.ibase.aist.go.jp/sdbs/ (National Institute of Advanced Industrial Science and Technology, 6 January 2011)

 

 

 

a.    Calculate the degree of unsaturation. (1 point)

 

(2 x 11 – 16 + 2)/2 = 4

 

b.    List the possible functional groups gleaned from the molecular formula. (2 points)

 

Alcohol, aldehyde, ether, ketone, phenol

 

c.    What is the functional group that the IR spectrum shows to be present in the unknown? (2 point)

 

Ether

 

d.    Propose a structure for this compound. (10 points)

 

           

 

2. Propose a structure for the compound that fits the following data: (5 points)

 

C₄H₇BrO₂             d = 1.08 ppm (3H, triplet)

                                    d = 2.07 ppm (2H, quintet)

                              d = 4.23 ppm (1H, triplet)

                              d = 10.97 ppm (1H, singlet)

 

 

 

 

3. Sketch the expected ¹H NMR spectrum of the following compound: (10 points)

 

 

           

 

           

 

 

4. When a solution of 1,3-butadiene in CH₃OH is treated with chlorine, the products are the following:

 

 

a.    Propose a mechanism to account for their formation.  (10 points)

 

 

 

 

b.    Which is the product of thermodynamic control?  (2 points)

 

 

 

 

5. Give the structure(s) of the principle organic products of the following reactions: (6 points)

 

a.     

 

 

 

b.     

 

 

 

6. Explain why borazole is a very stable compound. (3 points)

 

 

The molecule is aromatic as it is cyclic, planar, has a Hückel number of p electrons (6) delocalized over the ring system.

 

7. Name the following compound: (2 points)

 

 

4-nitrobenzenesulfonic acid or p-nitrobenzenesulfonic acid

 

8. Draw the structure of m-tert-butylaniline. (2 points)

 

9.  When benzene is mixed with an excess of D₂SO₄ (deuterated sulfuric acid) at room temperature, the atoms of hydrogen in the benzene molecules are slowly replaced by deuterium.  Propose a mechanism which explains this observation.  (6 points)

 

 

10.  Provide a synthetic pathway for the following transformation: (6 points)

 

 

 

 

11. Identify the diene and the dienophile that you would use to synthesize the following compound: (4 points)