Problems Set - Meeting #7

1. Referring to the reaction carried out in the lab, answer the following questions.

a. How is benzyne obtained in the lab? Why is it generated in-situ?

b. Which observations are you going to make during the reaction?

c. Which factors drive the reaction?

d. A double melting point is observed for this compound in many cases. How can this be explained?

e. Why is isopropanol used in the recrystallization step and not toluene?

2. A UV-Vis spectrum is also obtained for the compound obtained in this week's experiment.

a. Why does the procedure ask to use a quartz cuvette instead of a plastic cuvette this time?

b. What do you expect to change in the UV-Vis spectrum in comparison with last week's product?

c. Which concentration is needed for the UV-Vis characterization of the TPN? How do you prepare this solution?

d. Why is it important that the entire sample dissolves when running a UV-Vis spectrum?

3. Most Diels-Alder reactions are stereo and regioselective. Why does this mean? Give one example for both.